I have a kindle and buy most of my books through the local used bookstore but the kindle is great for all those free classics that I haven't read.

Don't rule out the nook. Since the nook supports ePub(with DRM) you can probably check out eBooks from your local library. Since the Kindle is a closed ecosystem that does not support ePub that channel is cut off from you.

Agreed, but the order is wrong. The truth is that you will almost certainly buy way more kindle books if you actually have a kindle