I also would be driving something newer if I hadn't peed-away my money stupidly in the last few years. Still, people think my '91 300E is a couple of years old rather than 13, and it's built like no other car I know. I like the old Benz for it's style and heritage, but it's not as reliable as my old Peugeot, which had the same amount of miles and cost half as much.
I think if I had a load of cash now I wouldn't buy a new or recent benz though. Probably a new Beemer or Range Rover instead
I did see a '95 E320 wagon recently though, and it looked like a really nice car. with the mileage your car has compared to the E320 I think it would be a good deal in the long-run if you can get a decent amount for your 300E. Maybe you can get it even cheaper if you tell them about the wiring harness/head gasket issues