Why is the NADA value so high on the 1985 and older Mercedes?

[86560SEL]

I have a 85' 380SE that I must sell. I was browsing on e-bay to see what they are selling for. I ran across one that is at $500. There was someone on there asking the owner a question- like- why are you selling so cheap, because NADA has it valued much higher. The car has some engine issues too. They state that is has a "cracked gasket cover". I have NO idea on that they are talking about. Anyway- I went to NADA to check the value on my 85' 380SE and it shows low retail at $6450! I am only asking $1800 obo and not even one reply from the boards here. Are the 380 4dr models that undesirable?

[Ara T.]

The 380 models do have a bad reputation with the whole single row timing chain business. Which I believe was solved by that year. Anyway, the 150 HP or so that MB pumped out of the 3.8 engine isn't much more than a diesel, might as well grab the diesel and get better fuel economy with no spark ignition crap to go wrong.

Edit: I believe the US spec HP was 155, i have seen some european specs as high as 218 HP but that seems rather optimistic.

[86560SEL]

Thanks. Yeah, my 85' has the double.