People keep saying that the open models are cheaper. Until recently that seemed true because they were smaller. And some of the best smaller models are still open and cheap. But K3 with its 2.7T parameters is never going to be really cheap.

But if it's 30-50% cheaper than Opus, provides same or better results and you can deploy it to your own premises or choose one from many providers and pay per token? It is, in general, measurably cheaper per task than Opus is.

Yes but at the very least they are an insurance against the big companies deciding to Enshittify their product.

For example if (when) open ai decides to 10x their price once every one is sufficiently hooked these open weight models will still be here.