Thanks for another link. I however am always baffled how some PDF are free are some are insanely priced. I am fine paying for work but why do certain people think just because it is on a fancy page it is worth 99USD (average book price is 18-20USD).

Presumably we should be judging the price based on the value, not the format it comes in.

A more pertinent question should be, what does refactoringui contain that is 5x more valuable than the "average book"

Yeah, partly inspired by them I dived into the UI/UX area.

But yeah a bit expensive though :)