I guess the value is in the eye of the beholder! One persons value, just might be slightly different then the other. Maybe! So I take it, you guys are making me an offer?
Rather than believe anything you've read here from experianced owners, take your information to Craigs List and eBay.
You may get lucky there, as the venue is quite differernt than you find in forums of folks who have fixed these type cars for years.
There was a W124 owner in the Phillipines about 2 years ago who had his average 124 sedan for sale on eBay for $100,000 as I recall.
I doubt that you will be any more successful at your asking price than that guy was with his...
He also promised a piece of a lucrative land deal as a part of the $100,000 purchase.
No idea if your just niave about the true value, or if your looking to make a killing, but your price assessment has no basis in todays market.
If you believe that the selling value goes up sunstaintially because you spent a lot of money to maintain it, you're in for a surprise.
This is not a real sought after collectable, maybe years from now, but in todays market there is just NADA and Kelly's to go by.
A low milage 124 convertible in mint shape, or a 500E is decent condition will draw the prices you are quoting, but coupes need to be perfect and you need a motivated buyer to even get top NADA value.
But head over to eBay and/or CL and find out for yourself.