How to go about upgrading iPhone

[bumzo1]

So right now I have a 3GS which I bought on launch day but unfortunately I'm not able to get a full subsidization until february of 2011 so I've decided to sell mine and pay the difference between that and the early upgrade fee. What is the best way to do this to get the most $ but be without my phone for the least amount of time? I also don't have an old phone that I can use because I switched from sprint. Also where and for how much should I sell it. it is a white 16gb in pristine condition (I'm about to get it replaced before apple care runs out)

Thanks

 

[elephunkman]

I usually sell mines a couple days before WWDC because most of the general public do not know what the conference is.

I go about craigslist and usually do about 375-450 cash.

 

[WiseMarley]

I would sell it a few days before wwdc and then buy some cheap phone to use in the mean time. I'm sure you could find a cheap at&t phone on craigslist for 20 bucks that you could throw your sim in to.