What to do with the number
The range is a conversation starter, not an invoice. If it's big enough to matter, the next step is replacing the estimate with evidence: a read-only bill audit that maps exactly where the waste sits (commitments, rightsizing, storage tiers, NAT, Kubernetes bin-packing and seven other line items) and ranks the fixes by ROI. Written findings land within 48 hours of access.
If you'd rather understand the discipline before talking to anyone: What is FinOps? explains the operating model, and the Cloud Billing & FinOps engagement page shows how the 90-day optimization actually runs. The methodology and the 45% figure carry the site-wide disclaimer on case studies.