I considered a topic like this for quite some time. Just sharing interesting ads that are worth talking about Can be from Seabreeze, Facebook Marketplace, Gumtree or any site really.
Starting with www.seabreeze.com.au/Classifieds/Windsurfing-Boards/~kduj4/Windsurfer-One-Design.aspx
Looks like a steal if you own a museum, not so much if you consider sailing this
"Has not been used for many years"
Yeah, we can see that!
I like the vintage , as new , Wind Action board for sale here. Perfect for the man room or garage. For the cost of a slab of beer.