I am new to Airsteaming too. I just found (and bought) a Safari 22 in California. Here is my advice.
Check Craiglsist every day. WATCH OUT FOR FLIPPERS. People who buy them, do some work on the interior, and sell them for a quick profit. And of course avoid Craiglist scams.
Visit this site. A great article on determining the value of used Airsteams.
Airstream Vintage Travel Trailer Link Library! - Restoration Channel
. This is the link to the main webpage, you will need to search for the article on determining used Airstream values.
Insist on an inspection by a qualified Airsteam mechanic or service center as a condition of purchase. The seller shoudn't have a problem with it if they are honest.
Know you tow vehicle's capacities. When you see an ad you can go to the airsteam website and find trailer weight ratings for most used Airsteams.
Be pepared to move quickly. I put in over 2,000 miles of driving looking at various Airsteams in California. I looked at 6 of them before I found one worth buying. I corresponded with at least 20 more sellers before determining a trailer wasn't worth the effort to inspect.
Buy one that was used and loved by the owner. If it has been sitting in a backyard or field for 15 years it will need a lot of work to get it up and running.
I saw lots of ads for gutted trailers. Avoid a total restoration unless you are retied or a person of leisure. If you work full time it will be 2+ years before you have a restored trailer on the road. Hundreds of hours and thousands of dollars to restore a trailer.
There are lots of used Airsteams out there. Be patient, make sure you are getting good value, and buy one that fits your needs and has the layout you want. Personally, I wanted the front dinnette setup, looked for it and found it. It took me four months to find the one I wanted.