How much is he looking to get? How much are you looking to spend, don't worry about a sound system, worry about mechanical issues. Have it checked by a mechanic. How many miles are on it. Head gaskets are a heavy job and can get pricey in labor charges.
1957 Buick Special Estate Wagon
1996 Mustang GT (sold)
1997 Mustang V6 (sold)
2002 Jeep Grand Cherokee Laredo (sold)
2007 Jeep Grand Cherokee