Where do you choose to indulge and buy new (to you) books? I, personally, shop at Half Price Books and Barnes and Noble. Half Price Books is where I pick up most of the classics for my sophomore classroom library. Since the books are used, I don't mind a student bending the cover, etc... Barnes and Noble is where I go when I need a specific book on a specific topic and Half Price Books doesn't have it. I'm planning a trip to Barnes and Noble this weekend because I need to pick up a book on zentangles.
Half.com has some great deals on books. I've seen books there priced at $1. Whenever I need to buy a number of books, I prefer getting them on half.com because you can't find them cheaper anywhere else. Of course I hate the waiting and at one time I got a book with some pages missing but most of the books I've bought [there] were in good condition.
I've now taken to buying eBooks more than actual books, and I love it. It's so much more convenience and cheap. I've never heard of both your suggestions. I just use good old Amazon, so it'd be interesting to see how they compare.
I think you can EASILY find FREE BOOKS in many different sites. Although I always bought my books from amazon.. I only do that when all effort has been exhausted online and there seem to be no other place to go but to BUY it from amazon.
I look around for an e-book copy because I am traveling right now, but otherwise I useLog In as they always do deals when you buy a few books, or I browse charity and goodwill stores for books. Due to space I have to be more careful about what I buy as there simply isn't room unless I buy a mansion... one day!
Kindle sales. I love trolling through Kindle sales and finding a book I've wanted to read for $2 or less. Under $1 I don't even think that hard about whether I want to read it or not, I just buy, buy buy. For $1-$2 it's probably a book I've been meaning to read for a while. Anything above.... forget it!
I have the Kindle Fire e-reader, so I get my books from Amazon. I find they tend to be very reasonable but also, they do have a lot of free offers all the time