Economy and Currency

Holding coins over a certain amount will start to incur actual weight to the coins (for example, every 25 coins above 500 weight 1 pounds in-engine), and they become an object in your inventory to reflect this.

Banks with tax rates exist at every domain to hold excess coins.

Silver, but per each domain (hemlocks, raven-claws, cordovan silver?)

On entry to new domain, your gold counter is converted into a physical purse of the other currency (so, if you transition from Barovia to Borca, your gold counter, which would say RC, becomes a purse of RC, and your gold counter is converted to 0 HL (hemlocks), unless you had a separate purse of hemlocks in your inventory, in which case it would reflect your hemlock coin count.

Domains have money exchangers with various fees for exchange, typically at banks.