HELP fix up S10 or buy car?

[73455transam]

My parents have a 1987 S10 that is in drivable but not great condition. It has about 150,000 miles, but the engine was replaced at 114,000. It is a 2.5 liter 4-cylinder engine with a 4 speed manual. The seats are torn up, I would have install a new sound system(can't live without music), needs new muffler, neesds AC redone and it needs a new headliner. There is some rust so it would need to be repainted, but it has not rusted all of the way thru anywhere, so I wouldn't need to replace panels. I need a cheap car, but one that gets good gas mileage and still performs decent. Could you please give me some advice on whether I should try to fix this up or buy something else like an early '90s Grand Prix coupe, or another truck.

Thanks