I have the chance to buy a good looking 300TE with 115,000 miles for 2500 dollars. I know about having it looked at by mechanics and the like, but my question beforehand is are these models known to be stout and reliable, or just a car that nickle and dimes you to death? I have owned both a 1976 300D and a 1983 240D, and these have been reliable other than cold starting issues (hence me wanting a gasoline Benz, and I've become accustomed to how easily the Subaru starts up) Are these good cars, what are any issues?

If its in great condition (~5% of '80s cars are) its a good deal. I bet it needs suspension work, head work, AC or climate control work and lots of odds and ends.

That price is getting near the bottom of the barrel. Do you expect the car to be in great shape?

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

As with the 560SEL the rear suspension can be a problem if it has not been maintained ie: fluid changes on the self-leveling system. It doesn't have the biodegradeable wiring harness either. I would go for it. $2500 seems like a good price if the car is in good shape.
There is a dealer here who has had a '91 190E 2.6 that has been sitting on the lot for over 2 years now who wants $6500 for it - here's the clincher - IT DOESN'T RUN!!! and the paint is horribly faded. A friend of mine showed interest and they refused to accept any less for the car. This is a 'supposed' reputable dealership - but not a MB one.

Most folks think the W124 is the best M-B ever made. However, I had a 1988 300TE and it was the worst car I've ever owned (I've owned 27 since 1964). Every possible component and system was a problem. Maybe mine was a lemon.