Good topic. For me it was godzilla timeframe on new games. I bought a Jurassic park premium for $7400 and then when Godzilla came out and the price increased to $8900 8 months later I was basically over paying those prices.
Similar to the OP I started buying a ton of games around 2014. Slowed way down recently now that premiums are in the $9000 range and games that I used to pick up around 2-3 are 4-5.