decomission cost and waste management costs are included and cheap. You should avoid informing yourself from some politically motivated websites and rely on real financial data like https://www.kkg.ch/de/uns/geschaefts-nachhaltigkeitsberichte... or check the Onkalo project

No, it's only expensive compared to every other generation source that is not expected to price in externalities. When I get to vent my waste product into the open air my mwh is way cheaper!! Who could have guessed? How much does a natural gas plant that captures all waste output cost?