NVIDIA was making big news a couple/few months ago that their new chips would enable full featured Android tablets in the $200 range. They suggested these tablets will be released by vendors this Summer.
If you can't wait the Acer iconia A100 is a decent 7 inch that you can get from Ebay or bensoutlet.com for around 180. It is refurbished tho. Got one for my wife and then my mom got one. They both love it