if everything else works and you have the time to play with it, buy it. I did that with my 95 e320. Change the fluid in the tranny a couple times to clean it out, and then drive between changes. still slipping? try lucas stop slip, still slipping? rebuild it. you'd still only be in it for 2500 bucks MAX.

__________________

77' 300D, "Cartman" SOLD @ 150K (didn't know what I had)
83' 300SD, "The Superdon" 325k+ @ 28mpg
95 E320 wagon, "Millennium Falcon" 231k+ @ 24 Mpg
95 E300D, "Sherley" 308k @ 33.69 Mpg, currently anticipating a head
99 Suzuki Intruder "Trudy" @ 45 mpg