The price difference is that google steals your data. That's it. OpenAI steals data, ask for money to use most of their models, and buy even more data from other companies stealing user data (like google and SO). Also indexing web pages is not even the "stealing" part of google, it's just not comparable.
Yes, training AI on user data for free then selling the end product is a reasonable thing to be concerned about. It'd be different if the product was free or the data was sold to them with user consent.
SO has announced a subscription-based service trained on user data for free, and not only there's not even opt-out, they're mass-banning users for trying to "opt-out" manually. Tell me one thing here that's not completely fucked up.