The 2.3L 8V M102 engine will not propel the 190E with much gusto, but the little mill is tough as nails. Auto boxes are on borrowed time after 150K-miles, but can last longer given good maintenance.
The main conern $$ wise on those older 190E cars is the cost of some common problems, including AC repairs and electrical problems.
Also, by this age and mileage, axles might become a problem, but used ones are not expensive.
I was in sales long ago, and bought several 190E 2.3 cars with lower mileages as they are decent on gas, easy to look after, and drove better than a Japanese washing-machine-car. I sold my last 1987 2.3 with 400,000km's on the odo (about 250K-miles) and hadn't done much to it. The next owner put some work into it, and is still driving it.
1998 C230 "Black Betty"