I have a 1990 Honda Accord with 220k miles. I bought it 40K miles ago.

It runs good at the moment but is due for various repairs.
-New timing belt, water pump, maybe tensioners (not changed in at least 40k miles)
-Needs new front bumper, new front turn signal light, passenger side mirror
-Outside of passenger side door is smashed up, needs new front passenger lock (lock works but can't open from inside due to inside handle and attachment being smashed up)
-Leaking oil from three places (do not remember exactly where)

Is investing $750 into this car which I bought for $900 a wise decision?

At what point do start setting money aside for a newer model year used car?

Thank you.