All the parts mentioned are not that expensive. As a matter of fact, I still have all the original springs somewhere in my garage which I can let go for cheap
. The rear control arms are around $30 a piece and normally you just need to replace one on each side. Do a search! The belt tensioner is more involved but, not difficult.
I have been thinking of replacing my car also but, when I looked at the newer vehicles and their PRICES
... I just keep working on my car and eventually my son will get it. On the other hand, if you are not mechanically inclined and the car is a money pit and/or the car is not safe nor reliable. It is time for it to go...Only you will know that point.
Good luck with whatever you decide!