I purchased a pin from Sean when i was a noob and although the transaction was smooth and Sean was pleasant to deal with I doubt I would buy another from him. Now that I have some experience fixing, tinkering and tearing down to the playfield I dont think the additional mark up he charges is worth what he personally adds to the game, IMO.
If you want to pay a premium for a nice, relatively problem free pin I am sure you will be satisfied.