Also let's not assume everyone in HN necessarily has money and comes from a wealthy country, in my country $22 is quite a bit to consider spending on a book, some developers earn well but others do not, or might not have a software job yet, if you are a student for example that might be 1/2 or 1/3 of your monthly budget.
For me paying something in dollars is not an option, because I don't have dollars and I have no way to buy them with my country's currency. Most people in the world are like me. Something americans and europeans don't realize
