I read the Economides book from several years ago. It has a lot of very reasonable tips. I wonder, though, how much they make from their book series, which inflates the earnings (but may be to help pay for college).
I bet their book doesn't have a tip on how to buy a BRAND NEW laptop computer for FREE! That's exactly what I did. And I don't plan on writing a book about that because I don't want stores to know how I did it or they might change their coupon policies.
p.s. Posting this via that very same FREE laptop.