Well, considering "best value for my daughter" and least costyly to own and operate, I'd have to recommend an E320, and get the year (97, 98 or 99) with the lowest mileage and best maintenance record.
And whichever year I purchased, I'd spend a couple hundred dollars and get the crankshaft balancer replaced. This part was updated in the middle of the 2000 model year.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".