What is a reasonalble price to pay a machanic to fix a blown head gasket on a 1995 corsica chevy.. I have had several people to say it was a blown gasket, but not what it would cost to fix it. I know each machanic charges differently, but what is reasonable ? Thank you...

Depends on which engine you have. Is this a 4 cyl or V-6? What size engine. If you provide more info, I could get you a better idea on what the cost will be.

Its an 6 cyl..

Basic parts cost should be well under $100, unless you need or should replace things like belts and hoses to insure worry-free operation after the repairs.
Labor is a much larger chunck: expect somewhere between 10 to 12 hours minimum for the basic head gasket replacement. Labor rates vary significantly from region to region but for heavy work you can anticipate as much as $90/flat rate hour, or more.
That is without any machine shop work if the cylinder heads and/or engine block, if neccasary.

Before I would grant any shop to perform the work, I would ask for things like written estimates and warranties. Also ask for technician credentials. You don't want just anybody doing this heavy line work.

Its an 6 cyl..

Parts wise you're looking at roughly $300 to cover the head set, head bolts, misc fluids such as oil & coolant, etc. Book time for replacing both head gaskets is a touch over 12 hours. If the repair shop or mechanic decides the heads need to be sent out to a machine shop to be pressure checked, resurface or to have a valve job performed, it'll cost extra.