I recently purchased a one owner 1990 Oldsmobile 88 with 54,000 original miles in close to excellent condition for $2,200. It has a brand new air conditioning system and has been serviced regularly. It has a strong 3.8 liter V6 and gets about 19mpg in mixed driving. Not bad, but not stellar either. Do you think I got a good deal on this car and would I be able to obtain a more fuel efficient vehicle for this price with a cold a/c system?
In theory a '90 model car is not worth 2200 dollars, but there’s exceptions.
Low mileage and cold air account for a something and it’s a much better deal than giving 2200 for a vehicle that is 10 years or so newer that has a 140k miles on it.
The 3.8 is a bulletproof engine and well maintained, it should go to 300k easy.
I don’t have a problem with this deal and any Oldsmobile “stigma” that some may attach about them not being made anymore should be overlooked.
Just about any part you may ever need can be found with no problem.
I look at this way. Buy a new car and you lose 2200 dollars in depreciation in a few days, or less. 
The low miles could be a problem when used as a daily driver. I had that problem with a car I bought from “the old lady next door”. Parts and hoses needed to be replaced after regular use since the car was used only on short hops. I did get a good enough deal to not mind.