One month ago I noticed the shifter in my '94 C280 began to feel mushy. The other day I was driving to school, All of a sudden my car went into neutral, I looked down and it was in drive. No gears would work. Just reverse. I checked the transmission fluid and it was completely gone. I refilled it and nothing happened.My car has 92000 miles on it (and I had the 65000 mile tranny service done) I had the car towed to a very reputable mercedes mechanic where I live and he said I need a totally new transmission. The car was driving perfectly fine before this happened, no warning lights, no rough shifting, nothing. In the year and 30000 miles I have owned this car I have replaced: The water pump, battery, rear bushings, wiper motor, strut bars, control arms, brakes, o2 sensor, wiring harness, and now this. aaahhhh!!!
Do C280's have a reputation for being so unreliable? Does it sound like my mechanic is right in his findings? How much should I pay for a rebuilt transmission? and also, does anyone know if a 94 E320 tranny will fit my car? Any info would be a big help to me right now. Thank you very much.

-Chris Whitsett