I want to upgrade to iPhone 4 and could get a 16 gig for $399. I want to sell my old phone. So, I bought my 16 gig 3GS in August of 2009. Back in November, it had some battery problem, and Apple gave me a refurbished phone under my warranty. My refurbished phone is in great condition as it has been in a hard otterbox case since I got it. I see iPhone 3Gs going for $300-400 on Ebay. If I sold my phone on Ebay, could I conceivably get that much? I'm sorry; I just don't know if there's something different about those phones on iphone.