97 GMC 350 VORTEX HEAD GASKET REPAIR

That's about right, but at $1500 you might want to look at replacing the engine with a good used model, aftermarket rebuild, or other new crate engine to avoid any issues with having the heads chcked and machined, along with the block and any align-honing. it's hard to say. If the mileage is really low then just replace the gaskets and throw it back together, but if the mileage is 60K or more then don't bother, you'll waste your money paying some mechanic to replace the head gaskets.