I had a 1984 500sel euro and it cost me an arm and a leg to maintain. It had the hydro-pneumatic suspension on all 4 corners. That cost me a ton of money ($700 just to replace 1 hydrostrut.
) I spent mucho dinero on the a/c system. I had a german indy mechanic replace the timing chain but after only a few months one of the cheap plastic rails broke. Consequently I bent valves on 1 of the banks and once again, spent a fortune on the car to get it running again.
If you did your homework you would find that these cars are plentiful and you can get them dirt cheap. Many of them sitting around in peoples yards. Chassis sitting flat on top of the old tires because the hydro-p suspension is spent and flat.
I would stay away from any of these IMHO.