Yes-
MGMAT SC is really good, specially for non-native english speakers. The concepts are very well described and detailed. If you are having trouble with SC, you *must* get this book. However, do note, that it does not have its own practice questions. Instead, it refers to actual gmat questions from OG11 and Verbal Official guide for practice.
The lowest I can find for a brand new
MGMAT SC is on buy.com for $15.44 plus shipping (shipping if free if you buy $25+ items with the orange truck item). Each book also gives you access to some online materials on their site. I have personally not seen the online materials yet, but I think it may be inaccessible if you have a used book.
If you are interested in buying the book, Buy.com is a good trusted source. I also have one for sale (it is brand new and never used - I bought two by mistake) for $11 plus $1.59 (media mail) shipping within Continental U.S. - email me at webmihir at gmail dot com, or PM me if you are interested. I can also send expedited shipping (UPS or Fedex) if required - I will charge the actual shipping that the UPS or Fedex website shows, not a penny more.
Walletless