This is probably the best book written on financial modeling in excel, definitely worth the $50. Comes with a great CD-ROM. The books strength is its illustration of financial models and implantation in Excel. Since the models focus on static solutions the book is probably of greater use in academics than in industry. It would be great if there was instruction about how to input real time data into Excel and implement the models dynamically. Of particular interest to me is the great VBA code given on the CD, namely the code to calculate autocorrelation, cubic spines, eigenvalues and eigenvectors. This alone was worth the 50 bucks.
There are some major deficiencies in this book. Noticeably absent topics include: bond portfolio immunization; swap pricing; forwards and futures hedging; the ARCH, GARCH and CHARMA models.
My background is in finance, mathematics and computer science. Unlike the guy above, I don't see any need for advanced mathematics in order to study this book. In fact I am sure you don't. The point is to make excel do it for you. However it will a lot easier for those who understand the finance and mathematics behind what they are telling excel to do. I am assuming that those who are considering this book most likely have taken at least one college level calculus course and one statistics course. But I don't think even that is necessary and definitely not stochastic calculus.