3 base offers + 4 RPG offers (3 distinct consumables + 1 relic)
RPG prices scale +3.5000000000000004% per stage index, capped at +45%, then round to 5 coins.
Local purchases spend session coins first and may cover the remainder with persistent profile coins. RPG inventory-full or unique-item blocks do not charge currency.
The three base offers remain owned by MerchantOfferSystem; ArenaRpgMerchantSystem complements them instead of replacing them.
Expedition checkpoints replay Speed ×1.12 and Damage ×1.18 as ordered persistent effects. Heal is immediate-only: only the resulting relative health carries.
P2–P4 use the authoritative co-op overlay with only the 3 classic offers. Payment uses shared run coins only; the Host never debits a remote player's persistent profile coins. Classic stock is team-shared, while the purchased effect applies to the requesting character. The complementary 4-item RPG shelf is not exposed by the current remote protocol.
