Somewhat weird Cold War era US textbook to learn Russian language for English speakers: it's full of surrealist humor, hyperbolising Soviet Communist realities. Allegedly, it has got a cult following.
camelcamelcamel is a cool (surprisingly, camel-branded) free online service to check the actual and past prices (historical prices, price dynamics etc.) for items on Amazon online marketplaces (including the regional sites).
For example, here is a link to the Amazon price history for the Fifty Shades of Grey (paperback book; somewhat NSFW, sorry):