Then set up a real money auction house and allow players to buy gold with dollars/euroThis is something very easy to homebrew
Come up with a coin system in your game world
Create a simple conversion table. E.g.
1 game world copper = 0.01 gp
1 game world silver = 1 gp
1 game world gold = 100 gp
Give out treasure in your currencies, and either you or the players convert to book "gp" to see what they can afford.
Mearls said in the recent Reddit "ask me anything" thread that they're looking into how to "flatten player wealth,"

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.