With only 77,000 miles on a 1996 Oldsmobile Achieva, is it worth repairing a head gasket?

What is your question?

Not sure yet if it's the head gasket, as there wasn't any water in the oil when I checked recently, but there was a slow leak in the hg a few years ago. Recently the car started leaking randomly (thought it was from overlow tank) & now immediate leaking & overheating. The mileage (77,000) is amazing for a 1996, so if it needs this major repair...is it worth putting the money into it??