For your first pin, I would really recommend NOT trying to buy a machine sight unseen and shipping it - even from a well-respected seller. The differences in expectations and skill/knowledge levels are likely to cause problems.

Think about how you currently handle a problem with a major appliance (i.e. refrigerator). Do you...
A) search on-line for the parts you need, order them, and then install them.
B) call a service repair guy to come and fix it.
C) buy a new one.

If you typically do (A), feel free to buy from some local "guy" who is selling a machine.
If you typically do (B), buy from a local dealer who can help you after the sale.
If you typically do (C), then maybe pinball ownership isn't for you (unless you have loads of money to burn).