[gsf]

Not in GCP if https://cloud.google.com/storage/pricing is to be believed:

> Generally, you are not charged for operations that return 307, 4xx, or 5xx responses. The exception is 404 responses returned by buckets with Website Configuration enabled and the NotFoundPage property set to a public object in that bucket.

[yencabulator]

Heh, charging for 5xx would be even more insane than charging for 403. "Our system is not working correctly at this moment. That'll be $0.25."