I see no point in keeping sources private in areas where the market is already huge! How many people are already selling XBOX360s?!?!?
There are so many buyers out there that no matter how much competition you are going to sell and make money if you buy at a true wholesale rate. There is no way not to make money.
Example: Lets say you have a contact that can get you authentic 4GB iPod nanos for $130 a piece. Even though there are thousands of auctions a day for the same product you are going to make money selling these no matter how much competition there is. Salehoo is here for people to help each other, not for the members to try and find ways to make money off of each other.