Let's see if I can add anything helpful for you.
I picked up an '84 last December with 72K miles for $2K at what I thought to be an excellent deal. Not as nice as yours but with some clean up work and about $1K invested in parts for service items I now have a solid 944 that I would guess I could sell for $5K.
Your car I would obviously value higher, $6K for sure. Now here is where the problem starts as I see it and as was alluded to in an earlier post. When you get over $6K you run into buyers who can also consider a 951 or later model 944. There are pros and cons to the '83 but I think it is the competition you face with the later, faster cars that will ultimately rob you of high end buyers. If you wait, you might find the right person who is willing to pay a premium for your car since they don't want the hassle of the turbo and just want a clean low mileage car. It will likey take finding that special buyer though. Personally, I think Ebay is a good choice to get wide exposure. I would also try advertising it with your local shops and local PCA region newsletter.
These cars make great candidates for entry level autocross and DE cars. That's what I'm using mine for and with low mileage and good condition you might find a buyer looking to start down that path. Good luck!!
Gratuitous pic
