Earlier quoted context omitted.
Can you elaborate on the pricing difference?
The long-term price difference can be hard to estimate. Suppose that your application is heavily dependent on GPT-4. OpenAI can double your API prices the next term. Or they can decide to stop supporting the model that you wrote all your custom prompts for. Or they could decide to disable your account because they feel like it. Unless it's for some fringe feature, building your business on OpenAI is probably a consid…
Say you're building on top of llama and Facebook decides not to update it any more or change the licensing terms (again). Say you're building on some other "open source" model and that project dies.
At least you can keep running the existing model rather than getting locked out over night. That's definitely much better. At least it's survivable. But you would still have to find alternatives and review/scrap all your custom prompts.