My opinion if your not one who enjoys working on your own car and researching forums like this a 1994 C280 may NOT be a GREAT choice.
But it is a great car, just that parts can be pricey and that six cylinder takes up a lot of space in that engine-bay so working in it can be tedious.

That trans leak and history have me thinking the owner wants to get rid of the car at this point because repairs are becoming too frequent and he doesn't want to put more money into the car.