iPad 2 Wi-Fi + 3G (64GB) - $370 for AT&T and $450 for Verizon.
These prices are for iPad 2 tablets in "flawless" condition, meaning no noticeable defects or scratches, no dust under the glass, and still in its package or like new.
Prices for units in good or broken condition naturally aren't as lucrative. An 16GB Wi-Fi-only iPad 2 in good condition ("works great but has some scratches or signs of wear") will earn you $250 from Gazelle, while a broken version (doesn't power on, has a cracked screen, or is missing parts) will net you $100.
Gazelle claims it's outshining the competition by offering higher prices for iPad 2 trade-ins. But I uncovered even better offers among some of Gazelle's rivals.