dont quote me on this, but i don't think the study guides will drastically change. my sister had the 2012 version, the study guides were not significantly different, maybe a few sections, but then again that was a 2 year gap instead of one.. All of the practice tests were almost identical. The only thing that you are going to pay almost $200-$250 more from the actual Dr. Collins site versus someone on SDN like myself is for more recent updates.
I have 4 updates (which are packets that include actual questions in each section from previous PCATs) and i saw SEVERAL questions from these updates and practice tests that were on my actual PCAT that i took last week.