Whatever Ingame-Currency they gonna use/we want to have.
I really hope, that there will be no insane "currency"-inflation going on.
In others words, it just kills the atmo, that every piece of equipment costs a huge amount of coins of "one type of currency".
Take Diablo for instance:
Everything drops gold and therefore gold is everywhere. And to purchase average equipment you need to gather tons of gold (which you can easily carry in your backpack...seriously?!)
I really hope, they keep a more realistic way, like it was done in ...
Legends of Aria, for example:
There is copper, silver and gold.
100 copper = 1 silver, 100 silver = 1 gold
If you loot copper and reach 100, it will not transform into 1 silver until you have been to a bank to exchange.
This means, if you gather "tons" of copper your backpack will be full eventually, so it is wise to exchange your money some time.
With that kind of system, it does not feel like a critical inflation is going on.
In LoA to buy a house is not cheap, but "only" requires some Gold (which would be several thousands of Coppers, remember 1 gold equals 10000 copper, again) and this feels more "realistic" in a fantasy/middle-age setting.
Hope you get what I'm talking about.