[petercooper]

I might be wrong, but I've inferred from OpenAI's pricing behavior that they use it to encourage people to migrate to more efficient models. The 3.5 Turbo pricing is maintained to encourage you to stop using it. Look at davinci-002's pricing, for example - it's very high for something that's relatively ancient.

[alach11]

It's also very likely that 3.5-turbo is more expensive for them to run than gpt-4o-mini. Models are getting smaller and more efficient. They just keep 3.5-turbo around for legacy support.

[hayksaakian]

exactly. the only people who would use 3.5 now are people who MUST use it due to some specification, contract or requirement.

You can charge a premium to people who aren't allowed to change their mind.