used iPads from Internet resellers
Cowboom is an online seller of used and refurbished electronics. It's a division of Best Buy. Cowboom offers decent deals on used iPads.
Here's one example:
original iPad, WiFi and ATT 3G, 64 GB storage, $280
guaranteed to be in working order
may show some cosmetic flaws
The 3G model includes the GPS chip, so you'll have accurate navigation. The 64 GB is helpful to store lots of downloadable maps, so you won't need to be in range of a cell phone tower to use a navi program.
Don't forget to google for coupons, they usually have a few floating around for $10 off or so. If you go with anything above a 6 you usually end up with a pretty decent product. Also, just something I've read that the products that come from the Texas location are usually in better condition then the ones coming from Cali....again just something I've read on slickdeals a few times.
used iPads from 1SaleADay
1SaleADay is an internet reseller that uses eBay to market refurbished electronics. Today, they're offering a 16GB iPad 2 with WiFi only for $330, shipping included.
The iPad is remanufactured by Apple, which in the past has meant a new battery and a new case, as well as fixes to whatever was wrong with the device. Apple sells reman iPads, too, but the same 16GB iPad costs $350 direct from Apple.
The difference in price may be that when you buy from Apple, you get a 1 year warranty. It's not clear from the eBay listing what warranty is available with the 1SaleADay product.