LoRAs or even full fine-tunes would be much cheaper than that, and with some investment in the right infra could be updated regularly. And at least LoRAs can be swapped in and out cheaply, making them usable in large-scale inference providers. But there seems to be limited appetite in offering this. Both Anthropic and OpenAI no longer offer fine tuning for current models

does lora do a good job at teaching the model new things that werent in the training data?

without trillions of examples of following instructions at a million context length, im not convinced the behaviour is in the weights to begin with