Trade with Players Medium Ground
Now the abuse part of it. Yes people will always try to abuse any priviliege that is good, hence why I suggest even if you are trying to do player to player trade it only allows you to sell the item at minimum price to the other player. There can also be an option where you can lock an item in marketplace where only a certain player can see and purchase it.
These 2 solutions can possible be ideas toward the right direction to pleasing everyone yet at the same time not allowing abuse
Server03 BadBoy
Brah..... Why you mad?
Fear the Power of the Collar Mute
*Pops Collar*