Deepseek v4 Pro feels like Claude Opus 4.6 in it's personality but here's what I did find out about costs:

I did cut loose Deepseek v4 on a decent sized Typescript codebase and asked it to only focus on a single endpoint and go in depth on it layer by layer (API, DTOs, service, database models) and form a complete picture of types involved and introduced and ensure no adhoc types are being introduced.

It developed a very brief but very to the point summary of types being introduced and which of them were refunded etc.

Then I asked it to simplify it all.

It obviously went through lots of files in both prompts but total cost? Just $0.09 for the Pro version.

On Claude Opus I think (from past experience before price hikes) these two prompts alone would have burned somewhere between $9 to $13 easily with not much benefit.

Note - I didn't use Open router rather used the Deepseek API directly because Open router itself was being rate limited by Deep seek.