ok so i think i found a way around the unbalanced trade problem.
player (1) is selling whips for 5 usd
player (2) buys a whip from p1 for real money
both players meet on en empty world in a general shop that has 0 people in
player (1) sells the whip to the store for 48k
player (2) buys whip for 78k
and the transfer is complete and now player (2) can sell the whip for gp or keep it
Think it could work?