The prices seem awful high for what you're getting.
If the F-14 is the one pictured in his collection, that's a sample F-14, not a prototype, and isn't worth a premium over any other F-14. A prototype F-14 has different cabinet art as pictured here:
There's another F-14 listed as a prototype on IPDB that is *not* a prototype, it has regular cabinet art. Games with a clear beacon and clear domes at the rear of the playfield are sample games, not prototype.
If the Earthshaker pictured on his site is the one you are considering, it appears to be a sample game, and may have a 'sinking institute', which would make it worth a premium of $100-250. It's hard to tell from his pics whether or not it has it.
F-14 prices should be well under say $1400 tops, for a really nice one.
Earthshaker prices should be $2000 or less. I'd feel better buying one at $1750.
If they are *true* high end restores, and I mean *true* high end restores - not glorified shop jobs - they would likely demand *more* than his price, if he is good at what he does. A high end restore has a great deal of labor and parts investment. Playfields are replaced or refurbished. Metal is often replated. An entire game is torn down to a pile of parts, all of which are replaced, refurbished, refinished, replated, cleaned, etc depending on what type of part it is. Every part is cleaned, to the point of someone being willing to eat off of them. That includes every square inch of wiring in the game.
A lot of people throw around the term 'restored', and one man's 'restored' is another man's 'shop job'.
That's my opinion, not a 'law' or 'rule'. I realize anyone can ask whatever price they want to ask, and I realize that a lot of retailers that sell to home owners need to tack on a premium price to cover the hassle factor
Seems to me, he is fishing.
The seller should be willing to provide some references who have purchased his work. Talk to someone who has had one of his games for more than a year. Ask how much they have played the game, how well it has held up, what problems they may have had and how they were handled, etc.