Wouldn't be so sure, at least not for a GPU-based system. Quick math for a 5090 running at around 500W generating 100 tokens per second (reasonable for Qwen 3.8-27B) is around 2-3 kWh for a million tokens, which is around $0.60 for some mix of off/on peak electricity rates.

This is in the same ballpark for that same model on openrouter (https://openrouter.ai/qwen/qwen3.8-27b), highly dependent on input/output mix. Deepseek is a much more capable model that you can't run locally on normal hardware, and their rates are insanely cheap ($0.04 / $1 per 1M).

And so far I haven't considered the cost of the hardware. I happen to have a gaming PC that can be put to use on inference when not gaming, but given these numbers I don't think I would buy new hardware to do inference at home. Unless my math is wrong, it seems you're way better off paying for Deepseek than running Qwen or some other locally runnable model yourself. Of course if you have specific privacy requirements or prefer something unique about a particular model you can run locally, the equation changes.