I really enjoy this guy's videos on various topics including the one above. If you have time, listen to his thoughts on used non-vintage guitar sales in these videos. He is a small shop owner and in other videos, discusses competing against the big box guitar sellers and other topics. I've never bought from a big box store. I like the personalized service I get from small shops.

https://www.youtube.com/watch?v=zkV42cQ1mwg&t=22s

https://www.youtube.com/watch?v=9hmS0xBmNvI&t=83s

I wish I had a quarter for every apocalyptic prediction (on many topics) that I've heard that never came true. 
 :roll 

I found the slump from earlier this year seems to be lifting. I just sold two high end guitars almost instantly, for more than I expected to get. And, ones I was hoping to buy  sold before going down in price.