Is this a lost cause or an evident loss that should be recouped?

I was in a car accident 1 month ago. I was completely stopped making a left hand turn about 5mins from my daughters school in Concord, MA. A man hit straight on from behind doing 20 mph. The only brake marks at the scene were from my car as I had my foot on the brake when he hit me. My car was 6 months old and for sale. We had listed the car for sale the month prior as we were planning a move to Maine and we only needed one car. We were going to break even and sell the car for what we owed, which was a little below KBB. Now that the car has been repaired by the insurance company I now cannot sell the car for what I was asking. There is a clear loss. His insurance company asked for proof of DV and I paid a 3rd party $300 to generate a formal report, I submitted proof that the car was for sale at the time of the accident and I was just denied any diminished value back to make the situation whole. Is this a cut and dry small claims? We are now moving to Maine in two days with 2 cars not 1