Well, it really depends on who you are selling it to. If you sell it to a player, they will give you around $2 to $4 dollars. If you are selling to a collector a n00b, they could give you $6 to $15. (the collector would buy for the lower end of that range.)
Sell it to a n00b....you will make a lot of profit from them. (Though cheating out a n00b is wrong.)