However, there are a lot of well priced Mooney 231's out
there that have their FAA approved known ice systems still installed
and working.

I was recently looking for a Mooney 231/252/262 with some sort of de-ice
and didn't find even one for sale. There were a few that I considered
adding TKS to, but by then I was getting close to the price of a Mooney
TLS/Bravo. So I just bought a Bravo with known ice.
---
Ken Reed
N9124X