My impression is that the workflow is supposed to be davinci for prototyping, then fine-tuning and downgrading to curie in several steps as you polish prompts and breakdown tasks (see https://github.com/openai/openai-cookbook/blob/main/techniqu...).

I haven't gotten beyond the davinci for prototyping tho. It's cheap enough that a month of tinkering a chatbot was $7 in jan.