The nature of these AIs is generally such that you can always throw more computation at the problem. Bigger models is obvious, but as I hinted earlier a lot of the current research goes more towards making various subqueries than making the models even bigger. In any case, for now the predominant factor determining how much compute a given prompt costs is how much compute someone decided to spend. So obviously if you pay for the "good" models there will be a lot more compute behind it than if you prompt a free model.