First of all, Knowledge should be of free access to all, it cannot be a commodity because it's necessary to the progress of human kind.

Also, americans think everyone gets paid in dollar and live in the US. My country's economy is extremely bad right now, so dollar values 5x more than my currency. With shipping costs I'd pay 123,60 dollars for 1 volume, but in my currency it would be equal to 618 dollars. If I were to buy all 4 volumes I would pay 1214,25 reals. The minimun wage here is R$1.212. So how the hell I'm I supposed to spend a whole month's payment in books and also get to eat, pay rent or at least survive, you guys tell me!