I've been thinking about joining, but it goes against the grain to pay that much.
I get most of my audiobooks from the library - we have a system here where we can order books from any library in the province. They get sent to our local branch, and we just have to return them there. I also check out garage sales and thrift shops, and have gotten a lot that way. Used bookstores tend to be a little too pricy for me, too (Lord, I'm cheap...) but sometimes I'll pick up something there. Online, you can go to Libravox, which is free but the quality is very very uneven - basically, it's just people reading public domain works into a mic.