Hi Gamejelly,
I commented in one of the Wanted: iPhone saying I would rather stick to an expert for iPhones etc, and by the tone of your reply you weren't very pleased. So I got thinking - your suppliers infomation is worth it's weight in membership fees, so obviously you won't want this kind of info been given away - but how about an Ask the Supplier form?
For items like factory unlocked iPhones there are complications like returns and warranties, but if you could offer members a way in which they could get their questions answered by the relevant expert (via Gamejelly.net) then buyers would have so much more confidence. You could put together an FAQ page for each category or something to cover all the standard Qs such as warranty and return info on the iPhones.
Obviously you're supplying a service, linking resellers and suppliers with a checkout system - so why not look at different ways to continually enhance it?
Just an idea, thought I'd let you know