I'm thinking I need to replace the rear upper control arms due to bad bushings and rusted bolts. This came about after replacing the tires and trying to get and alignment done. Alignment shop said you need to replace a few things in order for us to do a proper alignment. After many minutes searching the internet for the parts, I'm beginning to wonder if my searching is a futile exercise. It's a 1998 Volvo V70R with 170,000 miles that used to be silver but after replacing the hood and one of the rear doors is now wearing a cheaply done saffron paint job. Yes, it's a hooptie. No judgements please. I've had it 23 yrs and still love it.

 

How far off is the rear alignment?

How much faster will the rear tires wear?

For example If you consider your worn bushings are making your tires wear 33% faster, tires are $300, and last 30k.
So - you will spend $100 extra on tires every 20k miles on tires.
Upper control arm bushing replacement might cost??? It looks like those arms are solid and the bushings are pressed into the rear subframe. 9140469 and 1387226 in the subframe and 9157316 at the hub.
Plus labor might be at least many hundreds of dollars. Can the upper bushings be pressed into the subframe with the subframe still in the car?

 

Good way to think about this, cost vs benefit. I just purchased four new Continental tires that I felt were a good price, $460, and then with installation, total was about $530. Hard finding decent tires from known brands these days for much less that $100-120 per tire. The ones I replaced were Riken Raptors which go for about $90 per tire and had maybe 10-15,000 miles on them. I don't drive the car daily, probably average 5000 miles per year on it, so every 2-3 years I'll need to replace at least two tires if I don't do any repairs. Two rear upper control arms (not easy to find but looks like Classic Volvo Restoration has them https://classicvolvorestoration.com/p/control-arm-rh) plus the three different sets of bushings will cost me around $500-600 delivered. Then it's a question of how much a shop will charge to remove and replace the parts. My best guess is somewhere in the neighborhood of what the parts cost. Next step is to bring the car to a shop that can do the job and find out.