I have a 1993 190E, special edition, 2.3, 122K and I just sold one that had 52K on it. I love the cars I wanted to keep the matching set but we needed a wagon.
The M102 engine is a champ! Take a look at ebay and look at the mileage people are getting out of their 2.3s. I see 250-300K pretty often and that is with the pre-88 engines.
NADA does not reflect that the car is a Limited Edition and only 800 were made. I was able to get a $1100 premium over NADA for the Limited Edition that I just sold a couple of weeks ago.
The A/C system is not hard to work on like it is in the W124s. I always suggest getting a PPI and your dealership may even do a "Complimentry Health Check" for free if you don't want to spend $50-100 for the PPI.