Floppy, brightly-colored berets were popular in the late 60s and early 70s. I am unfortunately old enough to remember seeing some of them on the street, at school, on TV, etc. The character "Rerun", played by Fred Berry on the show "What's Happening!!", wore a red one.
You could see a lot of fashion from thw 60's and 70's in thrift stores all the way through the 90's. Then hipster style became mainstream and now all you can find in thrift stores is worn out suburban trash that was originally bought from a Ross or TJ Maxx.
Technically, a military surplus store could be considered a second hand store. What militaries use berets that could be considered "raspberry" in colour?