Barracuda spare back glass storage

Every time I go to a car show with my 66 Barracuda, I invariably have someone come up to make a comment about the back glass. Just this weekend, I heard "I bet you hope that back window doesn't ever get broken because they are so hard to find" or "Wow, if you ever had to replaced that rear window it would be really expensive if you could even find one". When I inform them that the glass is not as rare as everyone thinks and that I have a spare in my garage that I paid $40 for, they look at me like I don't know what I am talking about or they think I am lying. When I bought the spare I could have bought a second one from the same guy for another $40, but I couldn't transport two at the same time and did not feel like making another 5 hour round trip to go back to get it. One guy even said i must have bought that spare a long time ago because you can't get them that cheap anymore (bought it 3 years ago). I said "oh, have you been looking for one"? He said "No, I don't have a Barracuda, I just know they are not that cheap". He apparently has a crystal ball. Also, the last time I looked, there were three available on Craigslist in the Baltimore area.