I think that's a tricky question you're asking. I don't think those early 90's volvos are easier to work on, or rather, I don't find them easy to work on, but I've really only spent my time working on American Muscle. I think bang for your buck with safety and gas mileage will be a Nissan or Toyota, or even a Honda Civic from the mid 90's. They're not easy to work on either in my opinion.
really, you'd say they're safer than the volvo? I thought that early 90 cars would still be simplified enough to take basic components off (like alt, starter, water pump, etc..), i do know very little about cars, but i've fixed lots of tractors and other farm equipment