I agree to @balaji.ambresh‘s excellent feedback. E.g. for ChatGPT and many other LLM-powered applications this is the case also in my understanding.
Regarding the second point I would also point to these two sources / threads since they are relevant on the question how a cost-aware training of a LLM from scratch can look like:
- [Training LLM] blog post
- Best model and procedure to train a model that can answer law questions - #9 by Christian_Simonis
Best regards
Christian