What is a good, cheap tablet, mostly for reading on?

I have an ipod touch and read d&d (dungeons and dragons) books on it, but its a pain because the screen is so small. An ipad would be good, but i don't have $300 laying around. I don't want a nook or a kindle. The screens are slow, ugly, and black and white.I need something that is easy to navigate for quick rule checks and stuff. It has to support .pdf, as all of the books are in .pdf format. Also, WiFi support would be good, so I could print off character sheets or share the books with friends.