My pump total was $448 that was with the upgraded J2 86* Hinge frame and 2 day shipping. $750 is for the J2 I would say get the Series 5 for $400 unless you like the milling of the J2.
Not really, as with anything hard you just need to know what you are doing then it is easy. Here are some good sites to check out about timing and just how the autococker works.
Inline is where you grip with your front hand, it's vertical. The LPR is the reg that you can adjust your cocking pressure, it's parallel to the barrel, or horizontal.