if timing belt hasn't been done recently then it's up for timing belt change and all the stuff involved (WP, seals, gaskets, coolant, thermostat, belts, etc.). easily $500 at local shop with cheap parts of even more with OEM parts.
minor tune up would be a good idea too (A/F filters and spark plugs, get new wires if you suspect problems with old ones).
I also recommend all other fluids flush (transmission, differential, brakes, power steering) and an oil change with some decent oil filter
there is a bunch of minor stuff also which you can do, but don't have to like new rad cap, tank cap, PCV valve and grommet, rubber hoses replacement, etc.