How much to sell an iPhone 3G S for?

Any idea on a price I should ask for an iPhone 3G S?

The phone is secondhand and has had some usage, but is still in very good condition. I've done the basics; erased all personal information so the phone is back to factory condition, cleaned the handset, and even updated he iOS firmware to the current version. - However I have had to replace the USB data cable ($30).

I've been offered $50 for the handset, but I know I could get a better price on eBay.

Any suggestions on price are welcome.

Go on amazon and see how they are doing on there then either use amazon or eBay to sell personally I would sell on eBay much more security

Yes, i think you should sell your iphone 3G for $80 but it is only my opiniion. To sell your iphone you can visit the online store to advertise your product like ebay, fippcart, cellitused etc where it can help you to find the best deal for your iPhone 3G.
http://www.cellitused.com