Go to nadaguides.com and click on classic cars, you'll be able to get the price of it there. High retail is $4000. If you can find someone to buy it. You may be able to add a little more due to the fact that it has no miles on it.

I would check the fuel sending unit in the fuel tank. I'm not sure of the layout of the 220, but if it is in the trunk like most other MB's, remove the first aid kit on the rear deck lid and the sending unit will be in the top of the tank below the opening.

Have fun!