I'm going through the listing of reference materials that have been recommended. For most of these, there are multiple editions. Obviously, I would love to purchase the latest and greatest, new, upwrapped, etc. But, that would require me to get a 2nd job which would leave no time to study. In everone's opinion or experience, is there generally a big difference between editions of books. For the purposes of the exam, can I get away with an older edition (assuming it's not ancient)? Are there are newer editions that anyone specifically recommends over the older?? Thanks for your help (taking exam in October).