You can definitely get gpt-oss-120b for much less than $0.20/M on openrouter (cheapest is currently 3.9c/M in 14c/M out). Kimi K2 is an order of magnitude larger and more expensive though.
What other models do they offer? The web page is very light on details
K2 is the only of the 5 that supports tool calling. In my testing, it seems like all five support RAG, but K2 loses knowledge of its registered tools when you access it through the RAG endpoint forcing you to pick one capability or the other (I have a ticket open for this).
Also, the R1-distill models are annoying to use because reasoning tokens are included in the output wrapped in <think> tags instead of being parsed into the "reasoning_content" field on responses. Also also, gpt-oss-120b has a "reasoning" field instead of "reasoning_content" like the R1 models.
What other models do they offer? The web page is very light on details