The big one, OPT-175B, isn't an open model. The word "open" in technology means that everyone has equal access (viz. "open source software" and "open source hardware"). The article says that research access will be provided upon request for "academic researchers; those affiliated with organizations in government, civil society, and academia; and those in industry research laboratories.". Don't assume any good intent…
30B parameter models are already large enough to exhibit some of the more interesting emergent phenomena of LLMs. Quantized to 8 bits, it might be possible to squeeze into 2, better three 3090s. But the models also seem undercooked, slightly to strongly under-performing GPT-3 in a lot of tasks. To further train the same model is now looking at > 100 GB, possibly 200GB of VRAM. Point being, this is no small thing they're offering and certainly preferable to being put on a waiting list for a paid API. The 6.7B and 13B parameter models seem the best bang for your buck as an individual.