Love the concept, really needs some clever advertising to get people to know about it. I think a Facebook marketing campaign would be a good idea as most FB users seem to be the demographic that churn through phones at a hell of a rate.
Colours - I would think about making it brighter and (excuse this word but I think it best describes what I am trying to say) "funkier"
Search system - I would have a think about doing a text search option for the phone aswell as the brand > model version. It took me a few seconds to figure out what I was supposed to be doing - saw the brands but did not immediately see them as the search function (maybe as they are located where alot of sites put advertising - I saw brand names and ignired it as 3rd party advertising.
Again great concept - just feels a bit serious and corporate for something that I would expect to be targetted at the media / entertainment sector.
Good luck with it - this must work
Rich
Centure Pricing Management