I have had 3 different W124's. 2 Southern , 1 North Eastern, Boston.
I bought a '93 Sportline that had 250K miles for $3500 on a whim.
Car runs fine, but there are a couple of rust spots and the underside of the
car really is much worse than the southern cars.

This is an 11 year old car and a North Eastern car.

I would not even consider this car. You must consider the effects of the salt.
Like for instance the exhaust system. Not cheap.

Why not look for a car that has lived it's entire life in the South?
I recently spent a fair amount of time looking for either a '94 or '95 E class.
I was also open to an E420. Based on advice received on a couple of different lists from knowledgeable people, I also became open to '97 E320's and '96-'99 S320's.

Using Auto-Trader and a Car-Fax account, I examined various cars over about a three month period. For instance there was a '94 Black E420 in Birmingham that had every dealer service record from the beginning. Never auctioned, local car. Think about 12K$.

There were more than a few southern E320's for less than 10K$.

I ended up with a '97S320, local, dealer records, 106K, 11.7K$.

Steve