Most of the "old timers" on here will agree that a trailer is worth what you are willing to pay for it. I think it's sort of like a used car-- you can check blue book value, check the consumers guides for problems with a variety of years, check online for price/condition websites, etc., but what it boils down to is if this is the car/house/boat/horse/refrigerator or whatever that you have always wanted, you buy it.
Our trailer is a 67 (one of the years with curved windows- the expensive curved windows). We didn't know anything about Airstreams when we bought it, we just knew we wanted an Airstream and couldn't afford a new one. We thought we were getting a good deal... $3300.00. After all, the previous owners said that everything worked and they took it to the lake all the time. Without going into detail, let's just say that we are much more knowledgeable now about what to look for in buying a used trailer.
We have put approximately another $10,000 into it and it hasn't been on the road yet. Would we do it again, heck yes!! We love our silver whale, our escape pod, our retirement home....we love every little aluminum piece of him!
Buy what you want and enjoy. If you have a problem later, there's lots of people here to help you.
Beth and/or David
67 Sovereign, double bed, rear bath-"Moby"
2005 Dodge Ram 2500 Hemi, Quad Cab-"Ahab"
"Vintage trailer, vintage owners"