I have a blown head gasket

A new vehicle? Or just a used engine?
If the vehicle is in good enough shape that you want to keep it for a while longer than at least look into an estimate of how much to install a used (salvage yard) engine into it or rebuild the engine you have or just do the head gaskets and start looking for another vehicle.
I do not know why there estimate for replacing the head gasket/s is so high though.
I see the labor time for one side is about eight hours, actually for the left bank 7.5 hours, right bank 8.5 hours and for both 10.0 hours and at between $65.00 to $125.00 an hour labor, for a small shop or a dealer, the estimate I see would be $650.00 to $1,250.00 plus of course the price of parts, but nowhere near that $4,000.00 to $6,000.00.
I would call around and just ask about an estimate for replacing the head gaskets. You should not even have to bring the vehicle to them for more estimates.

Hi and thank you for the help. I am sorry I should have said the $4,000.00 to $6,000.00 was for a new engine and I do not remember if installation was included. They did not give me a price for repair just said it was a risk with that many miles that I could have problems with some other part of the engine within 30,000 or so miles. If I can get it repaired for anywhere the costs you think then I will get it done, but do you think there is a chance that other problems could go wrong after a repair like that? does that put some kind of strain on other areas of the engine? Guess that is a real toss up as anything can happen. Thanks again.

the concern I think would be if coolant entered the oil pan and diluted the motor oil long enough that the crankshaft and camshaft bearings (bushings) went without the proper oil protection long enough that it caused the beginning stages of bearing failure, so you should also be concerned about that.

Okay, thank you so much. that is probably what they were thinking too and just did not have enough time to explain it all. They are a great auto repair shop and I think highly of them and trust them totally but having it spelled out for me like you have sheds new light on it for me. I appreciate your knowledge and time to my worries.

You are welcome!