If it is new you got a great deal! I think the cover of mine says it was $69.99. Your links didn't work for me but I think that is because you bought the book so it is no longer available.
I got mine used with another book I wanted and paid $$$$
Back in the day I never would think books would be expensive, haha. As everything in life, it is all in the eyes of the beholder. Or is it supply and demand???? Or ???? Great find!