About $1150 for everything if it's less then that they may not be doing a good job
Yes.
parts and labor should run around $650
By replacing the whole gasket.
i am replacing the starter on olds 1995 aurora
Cracked intake manifold...
Irratic idling condition is indication of intake/inlet manifold gasket leak. Change gasket immediately. This particularly applies to EFI engines. Newaz.
About 450.00
I had some minor work done to my 04 and it cost about 200.00 to replace them!
It's supposed to do that.
Absolutely not. The two are not related in any way. If this was just a personal concern, just replace the intake manifold gasket. If this was what a repair station has quoted or already charged you for, Id go somewhere else or talk to a lawyer respectively.
diferential pressure sensor intake manifold plausibility
No, the head gasket is underneath the heads where they mount onto the block. Your intake manifold is bolted to the top of your heads. Some motors have coolant that circulates in the intake manifold ( I don't know what year or make your vehicle is ) so I would check my shop or repair manual. There could be a crack where the coolant flows through your intake manifold or one of the manifold gaskets may need replacing.