Well, I'm gonna rant just a bit. Maybe a lot!
I hope you'll excuse me, and I hope also that it's helpful.

First off, mid-80's 240s with mileage in the mid-200K range have a lot of life in them. Just miles and years alone don't make a car a problem to owners. Maintenance done and not done mean a lot. Rust of course is bad. These cars rarely have an engine or transmission go bad, which is usually what kills a car. All kinds of other jobs need doing, but hardly any are expensive enough that you give up on the car. So they usually get repaired, and keep going.

You probably need to help your wife understand this. Maybe she has reasons not to believe it, but as generalisations go, it's pretty good.

Doing as much work yourself as you possibly can is almost a requirement for these cars, if you want to keep costs down.

You probably can get yourself out of some maintenance work by getting a car with mileage in the mid-100K range, but it will cost you, unless you just happen to get lucky.

Any used car is going to need some work to be truly roadworthy. You can almost bet good money that it will need some work you don't know about - unless you pay a good mechanic with a lift for an hour's time to look things over.

So, with a budget of near $0, even a car whose price meets that budget will need some work to put it on the road. My round number estimate these days for decent-appearing older Volvos is maybe $1000. In most cases, if it didn't need at least that much work, it wouldn't be for sale!

The '92 is priced so low, it could maybe work for you. It needs a clutch, a shop will charge about $1000, I think. If you can do it yourself, probably under $150 for parts. Windshield, about $200. Try to get a Pilkington, and don't get the cheapest. I drove about 15K miles this winter (New England) on a new no-name windshield, it's all pitted now. I'm sure that not all glass is created equal.

You might keep 3 bricks. Insure one for "occasional use", and use it when another one needs work that has to wait for the weekend. That gives you the reliability your wife wants!