Did the same thing on a duplex in Meridian two years back after swearing off slabs, and the savings came out almost the same as yours once I added up stem walls and floor joists. The post tension part is what sold me, since the engineer spec'd it for our clay and we have not seen a hairline crack yet. Get a soil report first though, because I would not pour one on the wrong dirt no matter how cheap it looks.

Man, I get why that stung. A buddy of mine ran a Tuesday night poetry thing for years with this big list of prompts on index cards, and one night a guy told him the cards were doing the heavy lifting for him. He almost quit the whole thing. What he ended up doing was keeping the list but only using it when the group got stuck, like a spare tire instead of the steering wheel. Couple months later the same guy who complained was the one asking to pull a card because he couldn't get started. So maybe the notebook isn't cheating, it's just a tool, and your daughter is really saying she wants the prompts to bite a little harder.