Alright so I've been selling iPhone 4's on eBay for around 6 months.. I recently got approached on eBay buy someone who buys 20,000 iPhone per month and wants to do business outside of eBay without the fees. Of course I accept and am making a lot of money selling to him. Now I have someone who I buy iPhones from that wants to know who I sell them to. Now I don't want to just give this info away for free. Should I charge them a one time fee for giving them my buyer connection? A percentage of each sale? I'm lost as to what to do.