diff --git a/crates/game-service/src/home_mode.rs b/crates/game-service/src/home_mode.rs
index 99c9f05..d487534 100644
--- a/crates/game-service/src/home_mode.rs
+++ b/crates/game-service/src/home_mode.rs
@@ -38,6 +38,7 @@ impl HomeMode {
             build_avatar(profile),
             current_timestamp,
         );
+        logic.restore_free_chest_timer(profile.free_chest_end_timestamp);
         let cycle = ShopCycle::at(current_timestamp);
         logic.set_shop(cycle.seed, cycle.seconds_to_cycle, cycle.weekday_index);
         Self { logic }
@@ -253,6 +254,7 @@ impl HomeMode {
                 count: spell.count,
             })
             .collect();
+        profile.free_chest_end_timestamp = self.logic.free_chest_end_timestamp();
         profile.chest_id_counter = home.chest_id_counter;
         profile.free_chest_collect_count = home.free_chest_collect_count;
         profile.crowns_towards_crown_chest = home.crowns_towards_crown_chest;
diff --git a/crates/game-service/src/store/postgres.rs b/crates/game-service/src/store/postgres.rs
index fe0a315..b33cb6d 100644
--- a/crates/game-service/src/store/postgres.rs
+++ b/crates/game-service/src/store/postgres.rs
@@ -132,6 +132,7 @@ fn profile_from_row(
         chest_id_counter: row.get("chest_id_counter"),
         free_chest_collect_count: row.get("free_chest_collect_count"),
         crowns_towards_crown_chest: row.get("crowns_towards_crown_chest"),
+        free_chest_end_timestamp: row.get("free_chest_end_timestamp"),
         chests,
     }
 }
@@ -215,10 +216,11 @@ impl ProfileStore {
                  gold_resource_table, gold_resource_instance, gold_resource_name,
                  chest_slot_count, battle_count, win_count, lose_count,
                  npc_win_count, npc_lose_count, three_crown_wins, tutorials_finished, updated_at,
-                 chest_id_counter, free_chest_collect_count, crowns_towards_crown_chest
+                 chest_id_counter, free_chest_collect_count, crowns_towards_crown_chest,
+                 free_chest_end_timestamp
              )
              values ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16,
-                     $17, $18, $19, $20, $21, $22, $23, $24, $25, $26, $27, $28)
+                     $17, $18, $19, $20, $21, $22, $23, $24, $25, $26, $27, $28, $29)
              on conflict (account_high, account_low) do update set
                  name = excluded.name,
                  name_set_by_user = excluded.name_set_by_user,
@@ -245,7 +247,8 @@ impl ProfileStore {
                  updated_at = excluded.updated_at,
                  chest_id_counter = excluded.chest_id_counter,
                  free_chest_collect_count = excluded.free_chest_collect_count,
-                 crowns_towards_crown_chest = excluded.crowns_towards_crown_chest",
+                 crowns_towards_crown_chest = excluded.crowns_towards_crown_chest,
+                 free_chest_end_timestamp = excluded.free_chest_end_timestamp",
         )
         .bind(account.high)
         .bind(account.low)
@@ -275,6 +278,7 @@ impl ProfileStore {
         .bind(profile.chest_id_counter)
         .bind(profile.free_chest_collect_count)
         .bind(profile.crowns_towards_crown_chest)
+        .bind(profile.free_chest_end_timestamp)
         .execute(&mut *transaction)
         .await?;
         storage::sqlx::query(
diff --git a/crates/game-service/src/store/profile.rs b/crates/game-service/src/store/profile.rs
index 805d7d7..93402b4 100644
--- a/crates/game-service/src/store/profile.rs
+++ b/crates/game-service/src/store/profile.rs
@@ -48,6 +48,7 @@ pub struct PlayerProfile {
     pub chest_id_counter: i32,
     pub free_chest_collect_count: i32,
     pub crowns_towards_crown_chest: i32,
+    pub free_chest_end_timestamp: i32,
     pub chests: Vec<StoredChest>,
 }
 impl PlayerProfile {
@@ -88,6 +89,7 @@ impl PlayerProfile {
             chest_id_counter: 0,
             free_chest_collect_count: 1,
             crowns_towards_crown_chest: 0,
+            free_chest_end_timestamp: 0,
             chests: Vec::new(),
         }
     }
diff --git a/crates/gateway/src/bin/scroll-probe.rs b/crates/gateway/src/bin/scroll-probe.rs
index 87f232c..e143ae5 100644
--- a/crates/gateway/src/bin/scroll-probe.rs
+++ b/crates/gateway/src/bin/scroll-probe.rs
@@ -63,6 +63,9 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let pass_token = std::env::args().nth(4).filter(|token| token != "-");
     let claim_free_chest = std::env::args().any(|arg| arg == "--claim-free-chest");
     let desync = std::env::args().any(|arg| arg == "--desync");
+    let buy_chest = std::env::args()
+        .skip_while(|arg| arg != "--buy-chest")
+        .nth(1);
     let csv_root = std::env::var("SCROLL_CSV_ROOT").unwrap_or_else(|_| "assets".to_owned());
     match LogicDataTables::load_from_dir(&csv_root) {
         Ok(tables) => {
@@ -175,12 +178,36 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
                     }
                 }
                 println!("     random seed        {}", home.random_seed);
-                if claim_free_chest {
+                let checksum = home.home.chest_id_counter
+                    + ((home.home.spell_collection.spells.len() as i32) << 16)
+                    + i32::from(desync);
+                if let Some(name) = buy_chest.as_deref() {
+                    let chest = logic::LogicDataRef::by_name(logic::table::TREASURE_CHESTS, name);
+                    match chest.as_treasure_chest() {
+                        None => println!("!! no treasure chest named {name}"),
+                        Some(data) => {
+                            println!(
+                                "     buying             {name} for {} diamonds",
+                                data.shop_price()
+                            );
+                            let turn = EndClientTurnMessage {
+                                tick: 0,
+                                checksum,
+                                commands: vec![Box::new(logic::LogicBuyChestCommand {
+                                    header: LogicCommandHeader::for_account(home.avatar.account_id),
+                                    unused: 1,
+                                    chest,
+                                })],
+                                trailing: None,
+                            };
+                            probe.send(&turn).await?;
+                            println!("-> 14102 EndClientTurnMessage [LogicBuyChestCommand]");
+                        }
+                    }
+                } else if claim_free_chest {
                     let turn = EndClientTurnMessage {
                         tick: 0,
-                        checksum: home.home.chest_id_counter
-                            + ((home.home.spell_collection.spells.len() as i32) << 16)
-                            + i32::from(desync),
+                        checksum,
                         commands: vec![Box::new(LogicCollectFreeChestCommand {
                             header: LogicCommandHeader::for_account(home.avatar.account_id),
                         })],
diff --git a/crates/logic/src/commands/chest.rs b/crates/logic/src/commands/chest.rs
index 50f704b..1048a34 100644
--- a/crates/logic/src/commands/chest.rs
+++ b/crates/logic/src/commands/chest.rs
@@ -78,6 +78,10 @@ impl Execute for LogicCollectFreeChestCommand {
         if mode.avatar().arena.is_none() {
             return CommandOutcome::Rejected("the avatar has no arena");
         }
+        if !mode.free_chest_ready() {
+            return CommandOutcome::Rejected("the free chest is still on cooldown");
+        }
+        mode.start_free_chest_timer();
         mode.begin_claim();
         CommandOutcome::ClaimStarted {
             source: chest_source::FREE,
diff --git a/crates/logic/src/data/globals.rs b/crates/logic/src/data/globals.rs
index ae2f5c2..05e4bcf 100644
--- a/crates/logic/src/data/globals.rs
+++ b/crates/logic/src/data/globals.rs
@@ -9,6 +9,7 @@ pub const PRICE_EPIC_INCREASE: &str = "PRICE_EPIC_INCREASE_PER_ONE_BOUGHT_PERCEN
 pub const BUY_LIMIT_COMMON: &str = "BUY_LIMIT_COMMON";
 pub const BUY_LIMIT_RARE: &str = "BUY_LIMIT_RARE";
 pub const BUY_LIMIT_EPIC: &str = "BUY_LIMIT_EPIC";
+pub const FREE_CHEST_INTERVAL_HOURS: &str = "FREE_CHEST_INTERVAL_HOURS";
 pub const RARITY_COMMON: &str = "Common";
 pub const RARITY_RARE: &str = "Rare";
 pub const RARITY_EPIC: &str = "Epic";
@@ -34,6 +35,11 @@ impl LogicGlobals {
             _ => PRICE_COMMON_INCREASE,
         })
     }
+    pub fn free_chest_interval_seconds() -> i32 {
+        Self::number(FREE_CHEST_INTERVAL_HOURS)
+            .max(0)
+            .saturating_mul(3_600)
+    }
     pub fn resource_diamond_cost(amount: i32) -> i32 {
         const STEPS: [(i32, &str); 7] = [
             (1, "RESOURCE_DIAMOND_COST_1"),
diff --git a/crates/logic/src/data/typed.rs b/crates/logic/src/data/typed.rs
index 6c03be1..47aed73 100644
--- a/crates/logic/src/data/typed.rs
+++ b/crates/logic/src/data/typed.rs
@@ -46,6 +46,34 @@ impl LogicArenaData {
     pub fn index(&self) -> i32 {
         self.int("Arena")
     }
+    pub fn chest_shop_price_multiplier(&self) -> i32 {
+        self.int("ChestShopPriceMultiplier")
+    }
+    pub fn scaled_chest_price(&self, price: i32) -> i32 {
+        (self.chest_shop_price_multiplier() as i64 * price as i64 / 100) as i32
+    }
+}
+fn clamp_low_first(value: i64, low: i64, high: i64) -> i64 {
+    if value > low {
+        if value < high {
+            value
+        } else {
+            high
+        }
+    } else {
+        low
+    }
+}
+fn round_shop_price(total: i32) -> i32 {
+    if total > 500 {
+        (total + 50) / 100 * 100
+    } else if total >= 101 {
+        (total + 5) / 10 * 10
+    } else if total >= 21 {
+        (total + 3) / 5 * 5
+    } else {
+        total
+    }
 }
 impl LogicTreasureChestData {
     pub fn base_chest(&self) -> Option<LogicTreasureChestData> {
@@ -64,11 +92,27 @@ impl LogicTreasureChestData {
     pub fn arena_data(&self) -> LogicDataRef {
         LogicDataRef::by_name(crate::data::tables::table::ARENAS, self.string("Arena"))
     }
-    pub fn shop_price(&self) -> i32 {
-        self.root().int("ShopPriceWithoutSpeedUp")
+    fn price_row(&self) -> LogicTreasureChestData {
+        self.base_chest().unwrap_or_else(|| self.clone())
     }
-    pub fn speed_up_cost(&self) -> i32 {
-        self.root().int("SpeedUpCost")
+    pub fn shop_price(&self) -> i32 {
+        let scaled = match self.arena_data().as_arena() {
+            Some(arena) => {
+                arena.scaled_chest_price(self.price_row().int("ShopPriceWithoutSpeedUp"))
+            }
+            None => self.price_row().int("ShopPriceWithoutSpeedUp"),
+        };
+        round_shop_price(scaled.saturating_add(self.speed_up_cost_at(self.unlock_seconds())))
+    }
+    pub fn speed_up_cost_at(&self, seconds_left: i32) -> i32 {
+        let total = self.unlock_seconds();
+        if seconds_left < 1 || total < 1 {
+            return 0;
+        }
+        let cost = self.price_row().int("SpeedUpCost") as i64;
+        let total = total as i64;
+        let quotient = (cost * seconds_left as i64 + total - 1) / total;
+        clamp_low_first(quotient, 1, cost) as i32
     }
     pub fn unlock_seconds(&self) -> i32 {
         let root = self.root();
diff --git a/crates/logic/src/home/logic_home_mode.rs b/crates/logic/src/home/logic_home_mode.rs
index 29e5bbd..f8f1abf 100644
--- a/crates/logic/src/home/logic_home_mode.rs
+++ b/crates/logic/src/home/logic_home_mode.rs
@@ -108,6 +108,30 @@ impl LogicHomeMode {
     pub fn begin_claim(&mut self) {
         self.claiming_reward = true;
     }
+    pub fn free_chest_ready(&self) -> bool {
+        self.home.free_chest_timer.remaining_ticks <= 0
+    }
+    pub fn free_chest_end_timestamp(&self) -> i32 {
+        self.home.free_chest_timer.end_timestamp
+    }
+    pub fn start_free_chest_timer(&mut self) {
+        let seconds = crate::data::LogicGlobals::free_chest_interval_seconds();
+        self.home.free_chest_timer = LogicTimer::started(seconds, self.current_timestamp);
+        self.home.free_chest_collect_count = self.home.free_chest_collect_count.saturating_add(1);
+    }
+    pub fn restore_free_chest_timer(&mut self, end_timestamp: i32) {
+        let remaining = end_timestamp.saturating_sub(self.current_timestamp).max(0);
+        self.home.free_chest_timer = if remaining > 0 {
+            LogicTimer {
+                remaining_ticks: remaining.saturating_mul(TICKS_PER_SECOND),
+                total_ticks: crate::data::LogicGlobals::free_chest_interval_seconds()
+                    .saturating_mul(TICKS_PER_SECOND),
+                end_timestamp,
+            }
+        } else {
+            LogicTimer::idle()
+        };
+    }
     pub fn set_shop(&mut self, seed: i32, seconds_to_cycle: i32, weekday_index: i32) {
         let arena = self.avatar.arena.clone();
         self.home.shop_seed = seed;
diff --git a/crates/storage/build.rs b/crates/storage/build.rs
new file mode 100644
index 0000000..3a8149e
--- /dev/null
+++ b/crates/storage/build.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("cargo:rerun-if-changed=migrations");
+}
diff --git a/crates/storage/migrations/0002_free_chest_timer.sql b/crates/storage/migrations/0002_free_chest_timer.sql
new file mode 100644
index 0000000..2401259
--- /dev/null
+++ b/crates/storage/migrations/0002_free_chest_timer.sql
@@ -0,0 +1,2 @@
+alter table players
+    add column if not exists free_chest_end_timestamp integer not null default 0;