If you are tired of fixing cars, might I suggest a Toyota/Lexus? Volvos are maintenance happy. Meaning that the cars are only happy if they are religiously maintained, otherwise they tend to fall apart. Fortunately, they are easier to fix than SAABs.
The evaporator costs around $1200-1500 to replace. I am currently adding a can or two a month to keep mine cool. At $12/can, I can do this for just a couple of years. Remember, defrost requires AC to work effectively, so it is needed year round.
If the RMS leaks, there will be oil residue on the driver's side. Check for a drop of oil on the pavement before you move the car.
If the AC needs charging, it will cycle every 2-3 seconds, otherwise it will cycle every 10-15 seconds after startup. If you turn the temp dials to cold, make sure the fresh air center vent is closed to fresh air - otherwise you will get a mix and it may not feel very cold.
"Dealer" maintained? Service records, about an inch thick, is what you want to see.

Klaus
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(V♂LV♂s 1975 164, 1995 854T, 1998 V70R)