In addition to the above:

The W201 weak points at this age might also include the front and rear suspension bushings and links, if they haven't been refreshed by previous owners.

There are known issues with leaking heater cores, the same issue that affected VW and BMW from the same period.

Rust at the jackholes and in the deep wells of the trunk floor and at the front corners by the headlights can occur if the drain weeps were blocked by debris and dirt.