I don't think it is really worth buying, you can get a copy from a library and refer to it. It is too comprehensive , and I dont think for 10-12 CR questions we need to go thru such an exhaustive book (near to 300 pages). If you understand the basic concepts of CR it is good enough, afterall the GMAT is not whole of CR to spend so much time and energy on one specific topic. Well , this is my personal opinion, it may differ from others. There are however some good points which you can note from that book, but I would certainly not recommend anyone buying it