Cyberpunk 2077 Devs On $30 Expansion Price Raising Eyebrows
kotaku.com
The expansion costs nearly as much as both Witcher 3 expansions, and CD Projekt Red explains why

Tl;dr; expansion pretty much change whole game, reworks core game mechanics and adds whole new district. Plus Idris Elba and more of Keanu with expansion having almost as much lines as core game.