I got the CDP Royal Flush one. It cost like $200. I mainly got it just because of the 10 tests included, but it also included a crapload of angle ranking questions, cube counting questions, and hole punches. EVERY question of each test has a little 1-2 minute explanation which can be helpful at times. There are a few short tutorial videos for each section, (three for each part? so 18 total?)
I started studying for the PAT with youtube videos. You would be amazed at the amount of free stuff you can find online without spending a dime.