[cabmandone]

How did the Home Inspector determine the units were bad? If he's basing it strictly on age, that's not a good reason to replace them. I installed a Heat Pump in my home back in 1995 and it's the same unit outside the home today. Are there more energy efficient units on the market? Yep. Is the R22 in the older units getting expensive? Yep. But are either of those reason to spend thousands replacing the old systems? I don't think so.

If the older unit is for the second floor, I might consider replacing it simply because a more efficient A/C wouldn't hurt. Depending on the layout of the home, the second floor unit probably doesn't work all that hard for heat since heat rises.