You might want to visit Penn Wood - Airstream only park in New Bethlehem PA when they open.... April I think. PENNWOOD AIRSTREAM
Last time I was there they had a few used Airstreams for sale. Some owners have health problems. That is the usual reason for selling them.
Also, consider a visit to Colonial Airstream in Lakewood NJ - just across the river from Philly. You'll never see a bigger Airstream inventory.
Ask away, you're only 400 posts or so from being a grizzled veteran instead of a green rookie.