I was told by three facilitators that you don't even need to buy books if you don't want to. There are some students that use the resources that are there and borrow books from the MS2s. However, it depends on what you like and how you study. One facilitator said to get Netter's and Moores and MAYBE a biochem book... everything else you can just borrow.
-Ryan
PS Netter's and Moores together is about $150.