Greetings from the Florida Panhandle
Welcome to the Forums. We're glad to have you with us. As to Your questions, NADA is a poor resource when valuing Airstream travel trailers. I have never been able to figure out where they come up with their numbers Their prices are significantly below actual sale prices.
Used Airstreams that are in good condition sell for a premium. The best way to gauge value is to check prices on the Classifieds here on AisForums, Ebay, and rvtrader.com.
Good luck in your quest.
SuEllyn & Brian McCabe
WBCCI #3628 -- AIR #14872 -- TAC #FL-7
2015 FC 25' FB (Lucy) with HAHA
2020 Silverado 2500 (Vivian)