You have pay more for that

Not with GCS, you don't.

https://cloud.google.com/storage/docs/availability-durabilit...

Are you thinking of Persistent Disk (PD) and Replicated PD?

(I work on storage at Google.)

I was thinking of gcp regions in which case you do have to pay for it. For colossus cells within a single regions you obviously don't but I don't know enough how it maps it out down there and whether it just moves data around in the event of PCR