HowLongToBeat.com
I use this website before every purchase to decide if a game is “worth” buying at a specific price…
I “value” games at $1 per hour of entertainment, so a $20 game should have at least 20 hours of main story game play & $40 for 40 hours, etc.
It’s a VERY useful site because they also break things down as:
Main Story // Main + Extras // Completionist // All Styles
This gives me great insight in making my buying decisions.
I hope it helps you too!