Cheapest way is to hop down to your local bookstore for the afternoon and veg in front of a practice DAT using the Baron's or the Kaplan book. Oh yeah, there's also a practice DAT (not full-length) in the DAT registration packet).
Mid-range is to buy the Baron's. It's has errors and the Bio section is a bit tough to read, but it'll give your some practice. I think the book is $20 or something.
Best way if you want to get some hands on is to get the Topscore CD and practice with those. It's probably the same price as the Kaplan book, but the tests will simulate what the real exam is like. It's around $40 I believe.
I'm sure some other peeps on this board have better ideas. The way I actually prepped for the exam was I bought the Kaplan book, read through. Skimmed the Baron's. Took the Topscore exams and the one in practice book.
cheers mate...
