The people that know me in the game are well aware I am one of the wealthier players, this is my road to greatness in the art of merching:
1. first off i'm sure we all know that make sure what u buy can possibly be sold for more then u paid for it so if people have lower prices then the item is usually sold buy it or bargain for the price to get even lower.
2. Then make sure you bargain the person your'e trying to sell to, to raise there praise so you make more profit.
I have a lot more ways to make money but they are secrets but i would be glad to tell you in game