GCS for example and its the same with S3, costs space, egress and requests themself.

Data Storage 50 GB Standard Storage * $0.026 per GB $1.30 Network 10 GB egress * $0.12 per GB $1.20 Operations 10,000 Class A operations * $0.05 per 10,000 operations $0.05 Operations 50,000 Class B operations * $0.004 per 10,000 operations $0.02