Pre-training of a foundational model is what you're thinking of for the "absurdly expensive" part but fine tunes are extremely cheap and undoubtedly are being done constantly. (You can see just how cheap by looking at the papers for Alpaca, Vicuna, Koala, etc). Prices dropped from about $600 to $10 for smaller models. Guanaco, using QLoRA, fine tuned llama-65b in about 1 day on a single GPU.
Another way to empirically test btw is to search for all the articles pointing out what ChatGPT gets wrong (3 or 4). I recently tested those when looking for evals and it gets the large majority (maybe 80-90% of those are answered correctly now).
Pre-training of a foundational model is what you're thinking of for the "absurdly expensive" part but fine tunes are extremely cheap and undoubtedly are being done constantly. (You can see just how cheap by looking at the papers for Alpaca, Vicuna, Koala, etc). Prices dropped from about $600 to $10 for smaller models. Guanaco, using QLoRA, fine tuned llama-65b in about 1 day on a single GPU.
Another way to empirically test btw is to search for all the articles pointing out what ChatGPT gets wrong (3 or 4). I recently tested those when looking for evals and it gets the large majority (maybe 80-90% of those are answered correctly now).