The older/bigger GPT4 runs at $30/$60 and peforms about on par with GPT4o-mini which costs only $0.15/$0.60.
If you are currently, or have been integrating AI models in the past ~2 years, you should definitely keep up with model capability/pricing development. If you are staying on old models you are certainly overpaying/leaving performance on the table. It's essentially a tax on agility.