All the crap new Pythons/King Cobras did was drop the bottom out of the market.
I sold a bright stainless 6" unturned (hangtag in the plastic) to build an MPA rifle for $4K in 2017? or abouts there. Now that same gun sells for about half. The new ones aren't hand polished and hand fitted and only look like the originals. I still have several in boxes bought in the late '70s/early '80s. I wish I would have bought one of the 8" .38s, but nobody wanted them back then...
It wasn't just Walking Dead. I also heard there was some first person shooter computer game(s) (have no idea which one(s)) where "The Python" was a one shot kill pistol, so all the gamers thought it was all powerful.
They'll always be worth much more than they were new, but that whole Colt craze was tulips there for a while. I'm glad I cashed in a little at least. I guess I should have sold them all and bought them back now for half, but I honestly think they're a superlative pistol, and love taking my shooter to the range. It's lost a lot of blue to the holster, as it sat on the hip of a PA State Trooper for 23 years, but it's a straight shooter. Still has the nail polish and white out on the sights. I've never messed with it.
All good condition Colts will go up and down in price, but stay gold coins. I only shoot the one pistol, but I keep the rest for an off the books rainy day fund. There will always be people who will buy new/old stock iconic pistols.
IMO the old Colts are better than the old S&Ws out of the box, but the smoothest, best shooting pistol I've ever shot was and N frame and the duty pistol of a retired FBI guy that "had some work done to it". I never found out what that meant, but the DA pull was like a longer, but just as pure and glassy break, SA pull. It was a dream to shoot it either way.