We do have some idea. Kimi K2 is a relatively high performing open source model. People have it running at 24 tokens/second on a pair of Mac Studios, which costs 20k. This setup requires less than a KW of power, so the $0.8-0.15 being spent there is negligible compared to a developer. This might be the cheapest setup to run locally, but it's almost certain that the cost per token is far cheaper with specialized hardware at scale.
In other words, a near-frontier model is running at a cost that a (somewhat wealthy) hobbyist can afford. And it's hard to imagine that the hardware costs don't come down quite a bit. I don't doubt that tokens are heavily subsidized but I think this might be overblown [1].
[1] training models is still extraordinarily expensive and that is certainly being subsidized, but you can amortize that cost over a lot of inference, especially once we reach a plateau for ideas and stop running training runs as frequently.