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.
If Idris Elba is as annoying as Keanu then I wish they'd used that money for the game rather than stupid actors who have no relevance to it. Silverhand is one of the many reasons why I really dislike the story. Either way, not going to buy this shit until it's 80%+ off or something.