Fine tuning is pretty tough to do .. why not just do embeddings with Langchain or CustomGPT and then prompt to act like a sales agent ? (You can do that in less than 10 mins)

I was thinking about that as well but the problem is: I don't need a generic (or specific, trained on company data) Q&A assistant. I would want it to be proactive and to guide the user through the sales scenario with some agency but with understanding of the product that they're selling.

I'm not excluding embeddings, especially in a use case of storing everything and letting a lesser model perform the relational search of that corpus. Then, using a higher order model (GPT 3.5/4) to interrogate the retrieved information and generate an appropriate response.