at 72k you r looking at new struts sooner than later. that will cost anywhere from 350$ to over a grand for oem replacement, pending on if u do the labor or not. most other major maintenances will be at 100k+. it comes down to what u want, either a higher mileage car with maintenace costs or a new car with nothing but a monthly payment. this is all assuming u r not modding it out.
im at 145k n havent had any major problems n costs. new radiator, struts, timing belt, general tune ups, had a power steering leek. going to replace the clutch n fw at the end of the year. all in all its been nice not having payments for the last six years n i like working on it myself.
i cant comment on the trans issue ur having cuz i havent had an issue. ive seen ppl post good n bad bout the trans. seems mostly those with mods r running into poblems.
if ur not into ur third or fourth set of tires by now, that'll be up soon. of course, like stated all ready, youll have to put some $ into it to get a fair shake on the sale.
think about if ur trading in or going private. trading at dealer will be a loss. private sale might get u what its worth if ur trans is fixed. lots to consider.
fix or sell, ur still gonna have to shell out some dough unless u just sell at an adjusted cost. buying new means shelling out a downpayment n then a monthly bill for three to five.