Monetary costs are not the only costs in this scenario. One of the costs of destroying the mountain is that the area no longer has that mountain. In exchange for warehouses and parking lots or whatever an "industrial area" means.
There's so many good stories where some brave hero has to give their life to save the day, and because of their sacrifice, the good guys win, the survivors cheer, and everyone lives happily ever after. But the hero never gets to see the ending. They'll never know if their sacrifice actually made a difference. They'll never know if the day was really saved. In the end, they just have to have faith.
See I was thinking he retained an infinite level of power, but only within the incredibly small domain of being able to finagle over any chair, physics be damned.
Fuuuuuck, I forgot all about those. Lone Wolf, Wizards Warriors & You, Fighting Fantasy... They were like a bridge between CYOA and D&D.