First, this is a great mathematics dictionary. I've bought a number of math dictionaries over the years and this is the best I've come across. It's concise, clear, and complete. I'm not a mathematician, but I doubt it could be faulted for lag of rigor. Even so it is accessible to the non-mathematician. That said, the pricing is ridiculous. I bought the 1992 paperback edition in 1994 for $25, and that was retail, and not from a discount bookstore. Unfortunately I lost the book somewhere along the line, and am looking to replace it. However, I refuse to pay $125+ for it... it's not 10 times better than other *paperback* dictionaries that are available.