Why not buy a cheap Nexus 7 first generation and put it in a decent case?
I'm looking at picking up the Amazon Fire tablet for Kid's - the 7" is $149 with a free year of Amazon's "Freetime" service, which gives you access to 5,000 games, books, movies, learning programs, etc.
http://www.amazon.com/Fire-Edition-D...dp/B00LOR4928/
Plus it has a rubber case and a 2-year no-questions-asked warranty - if it gets broken, Amazon will replace it. Seems like an excellent investment at less than half the price of an iPad Mini!