"You get what you pay for" comes to mind. If the quality of the ereader, and it's rendering of the books, is sub-par, will you enjoy using it for that year??
Personally, I prefer to pay a little more for better quality. That includes an extended warranty (I have kids-who-are-not-so-careful-with-devices syndrome). Then the reader lasts for several years - I still have an iPad 1. I have started eyeing the mini...I think I'll wait until the retina-mini comes out this spring.