You just hit the nail on the head, it will be done in one day so the price is reasonable. Take the day off and ask him to give you some tips on laying out the shop, wiring so you can do it all yourself.
I would recommend putting in a full panel instead of a sub. 12 slots fills up pretty quick especially if you have a few machines on 220. I put a full panel in with 40 slots and used 30 of them so the more the merrier.
Don