About 2 months ago I took my 2002 Saturn SL1 (10200 miles) for an oil change. The mechanic informed me that there was some oil in the coolant. I checked the coolant today and it appears to be congealing with what looks like oil. The mechanic in question told me that the Head Gasket needed replacing whic is fine however he qouted me that it would cost $2500. Is this quote accurate? Is it really that much for a small engine vehicle?