What's my 300CD worth?

I have been debating on if I want to sell my 1979 300CD, but I am no idea on how much to ask. I am starting to want something a little bigger, most likely a 240D.

The car has 166,500 miles, and seems to have decent compression and a rebuilt transmission. Everything is pretty good shape, but the gaskets around the windows probally should be replaced sometime. The paint is cracked on the hood and trunk, and right above the sunroof. The interior is in ok condition, with the normal wear these cars have. The AC doesn't work, and the A/C servo still works, but sometimes it acts up and either blows out very hot air, and sometimes not work at all. I am thinking of asking $2500, which is how much I paid for it a few years ago. That is probally too much, does $2,000 sound like a better asking price?