You can get the steel shim gaskets for around $8 a piece if you look around. I hope there are still some left, I might've used them all. I have no idea what the job costs. I know it costs me when I do it myself $20 for the 1200 intake gaskets, oil change and filter, silicone, and $20 valve cover gaskets.
Is this on the car that you want to buy? If so I would have secound thoughts. Could be a bunt piston, with out a leakdown test there is no of telling. (almost)
To have a head job (basic) both sides is about $800.
If you're looking to buy a car, I would really try to get one that's never had the heads off. They are never the same once the heads have been off. Just my experience. The factory must have a better way of torquing them.