I bought my iPhone 3G when they came out and sold it two years later (a month before the iPhone 4 release) for $250. It even had a crack in the back. The reason is because people who buy them usually use them on a network that is not officially supported. They are buying them "unlocked". To buy a new iPhone unlocked it's something like $650 from Apple.
I find resale value for Apple products generally great. It's much better than resale value of say any Android device. Primarily because there's a new Android device every month. And there's 1 new iPhone every year. So if you time your selling correctly (a few weeks before the announcement of new iPhone) you will get a very good price.
I bought my iPhone 3G when they came out and sold it two years later (a month before the iPhone 4 release) for $250. It even had a crack in the back. The reason is because people who buy them usually use them on a network that is not officially supported. They are buying them "unlocked". To buy a new iPhone unlocked it's something like $650 from Apple.