Since ipad 4 has launched, the price on 3rdgen iPads have decreased. Try eBay or craigslist I've seen them less than $500. Since its ipad 3rd gen which released on April, the ipad will still be under apple warranty.
The best buy near me had a few Verizon and AT&T 16gb iPad 3s open box available great price too. I say if you have any best buys in the area give them a shot as well.