Heres a bit of history, that may be interesting...What happened back in the 90s caused a crash in comic book collections, and almost ruined publishers. Silver and gold age comics were selling at high end auctions for lots of money. When new collectors saw the prices they rushed out and bought multiple copies of newer comics. The silver and gold age comics sold at high prices because they were rare (there was an effort to recycle them for the war effort during WW2). The newer collectors hording multiple copies of newer comics made them much less rare, and prices didn't rise. They eventually figured this out, causing the crash. It took major publishers like Marvel and D.C. Comics joining with movie producers to revive interest.
That is exactly the history I was referring to, but considering this was just a glossary, I didn't want to overwhelm new readers. I plan to do an article about this at some point, as well as one on the comics code authority! Thanks for explaining this to everyone!