That is a lot of money for a '93 - the Kelley valuation for a private sale is $13.4K - but it sounds like a very clean low-mileage car. Try a $12K offer.
If you like the 300E's, then an upgrade to a newer car can make a lot of sense, especially if you are looking at doing a lot of work that doesn't add much value to your car and you are able to buy a new one that doesn't require any work for a few years.
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe