How do I sell my 2.5 year old iPhone 3GS 8 gb factory unlocked running iOS 6.1.3.
No bill. Des come with original box.
You can get approx ~5-5.5k assuming you have all accessories when you say, you have the original box. I doubt any one would be willing to trade this one with iPhone 4/4s. In that case your best bet would be to sell it.