Iv'e owned a W124 (sold w/ 236k), and now have 2 W210s (sedan with 175k and wagon with 205k). I would agree with the W210 recommendations. Go for a facelift 2000-02 or 03 for the wagon). Also look for transmission service and no rust. There are nice examples for little money.
For some issues you need the MB software to fix them. It also makes it easy to troubleshoot. Any good independent mechanic has one or they can be purchased by individuals and are relatively inexpensive. They also work for many other models. I only recall using the software twice for both of my W210s. Once to clear limp home mode when I spilled coffee on the shifter and once to identify a faulty sensor (out of dozens of possibilities).

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07 E350 4Matic wagon, 06 S430 4Matic, 99 SLK 230
retired W210 (x3), W124, W126