Young FW full timer needs a new rig 4 months out

You are going to take a hit by trading. No way around it. My suggestions
1. Remodel the bunk area to suit your needs.
2. Search "making rv a/c more efficient" and you will find tons of information. #1 issue, in my opinion, is poor separation between the hot and cold sides of the a/c. While the a/c is running, stick your hand in the return side and feel for cold air leaching through from the cold side. Seal it up however you can. I used metal duct tape. Made a big difference.