Date registered: Sep 2004
Vehicle: 2014 E250 Bluetec 4-Matic, 1983 240D 4-Speed
Mentioned: 3 Post(s)
Quoted: 256 Post(s)
There is no magic number of miles after which you will suffer persistent mechanical problems with a W202 chassis. In fact, the W202 seems to be from the period just prior to MB's change of the guard, as I think it was the last car before the W210 chassis, which was the beginning of the dilution of the brand with Chrysler's sourcing approaches and the advance of styling and model proliferation to the point where reliability was taken for granted, so it likely suffers less from such influences than later cars, even present products.
Any MB from the time since you were born can last several hundred thousand miles with reasonable maintenance. Oil changes with a decent quality oil, and intervals selected based on the quality of the oil, air filter changes, and then keeping after issues that come up. It is highly unlikely you will spend more than $700 to $800 every 6 months to keep yourself in tires, and well maintained. That is at max about a third of your annual car payments, and you will most likely still have about $500 to $700 for annual maintenance for a new car (tires, oil changes etc.).
Save your cash, follow the advice of your parents. They seem to be pretty capable of providing sound advice - why don't you pose some of these other questions to them? At least you can count on the fact that they are going to answer with your best interests, as they understand them, in mind. Jim