I sold an old 15 gig Ipod at Nextworth and they did send me a check and did everything that they said they would do. However, when I input my info (serial number, condition, etc) they quoted me a higher price than they eventually sent me. The Ipod stopped working and I indicated that and they quoted me something like $20 (they pay all shipping etc) since it wasn't worth anything to me I sent it in, they ended up sending me $9 for it saying the drive was bad.
The only problem I see is once they have your Ipod etc, there isn't much you can do to negotiate.
As long as you know this going in I think you'll be okay, I've read other reviews on them and I feel they are legit and there are no concerns in regards to them stealing your Iphone, but I wouldn't guarantee that you'll get the price you want.
Good luck
Eric
