How much 1 swagbuck worth?

I haven't been with swagbucks for while, and lately I get back to work with it, and try to earn some swagbucks for exchange some gift from amazon. I was curious about how much one swagbuck worth actually? If I have 800 swagbuck, approximately what can you get from it? If I want to get a book from amazon, like a paperback, how much swagbuck should I need to get for it?