Oh, that sounds really cool!! I haven't actually used chatGPT so I'm not familiar with the pricing or free limitations of it.
Recently I've been really enjoying LM studio for D&D related things. I've created separate conversation threads for different topics, plots, and characters. So, when I ask a question it already is aware of the context behind my ask and it tailors the response accordingly.
For example, I recently had a one-shot and I knew I wanted to have a powerful sorceress who controlled minds. So I spun up a new conversation and typed out the basic info. Then I asked the LLM what her favorite form of torture was, how many people she had mind controlled, and what her lair might look like, etc. It worked better than I thought it would, although some of the responses seemed pretty cookie cutter 😅