What can I expect to get for my Iphone 3G?

I cancelled my contract with ATT because the reception was always bad, my 3G network never worked and I was sick of all the little bugs. Now I’m selling it. What Can I get for it? I know everyone’s trying to get their hands on unlocked ones. It’s not unlocked but it has no service on it. i saw them on ebay for 700–1000 dollars but I want to sell it locally.