I agree with the post by @VDCdriver above, expect the head gasket replacement bill to be well above $1000. On this car, if less than $2000 I’d be surprised.
If you think about it, it’s odd that a head gasket could cost so much, after all it is just a gasket. A weird shaped piece of paper is all it is. How much could a gasket cost? But of course the cost is the labor involved. At $100/hour, it adds up quickly. Removing the cylinder head may involve both the intake and exhaust manifolds too, and the fuel injection system components, and removal of other stuff to provide the needed clearance. Plus they may recommend to replace stuff not broken, simply b/c everything is already taken apart at the time.
Has the engine ever severely overheated? If so, other parts of the engine might be damaged or have warped and need resurfacing. Fixing those may add to the cost.