They said 1.5 tokens/second. 1 mil tokens is 667k seconds is 185 hours per million tokens. 1kW * 185hr * $0.45/kWh = $80 per million tokens. Again, assuming 1kW, which may be high (or low). The cost of the physical computation is electricity cost.
But you can run and experiment with any model of your liking. And your data does not leave your desktop environment. You can build services. I don't think anybody doing this is doing it to save $20 a month.