You might find rear shocks for $75-100ea, but if you can buy Bilsteins (front) for newer strut cars for that much---let me know.
Either Sachs/Boge or Bilstein can be OE and both are quality parts. All MB cars w/leveling use Sachs strut legs. Most of the TRUE sportline Struts were Sachs!!
A W210 chassis with 42,000mi should not need this type of repair for another 50k mi.
MERCEDES BENZ MASTER GUILD TECHNICIAN
ASE MASTER TECHNICIAN
27 YEARS DEALER M.B. Shopforeman
190E 2.3 ITS RACECAR
1986 190E 16V