Tool

Five-year cost model

Most DDoS purchases are decided on a year-one number and regretted on a year-three renewal. This adds up the whole five years with every line visible. The value is in the lines a quotation does not contain, which are marked below.

One-off

Hardware or first-year subscriptionFor the specific model quoted, not the familyHA pair or second unitoften forgottenOften omitted from a first quotationSpares and RMA coveroften forgottenWhat a replacement costs and how fast it arrivesInstallation and integrationIncluding the routing work around it

Per year

Support and maintenance, per yearConfirm the renewal percentage, not just year oneLicence or capacity subscription, per yearAsk whether capacity is physical or licensedUpstream scrubbing or transit retainer, per yearoften forgottenThe tier that answers saturationAttack-time overage, per yearoften forgottenWhere a cloud tier bills by event or volumeRack, power and cooling, per yearTwo units if you counted an HA pair aboveStaffing, per yearoften forgottenThe fraction of a role this layer actually consumesTraining and exercises, per yearoften forgottenIncluding the tabletop the runbook needs

Adjustments

Annual escalation (%)Renewal uplift, or currency movement where you buy in a foreign currencyMid-term capacity upgradeOne-off, in year three, where growth outruns the original sizing

The arithmetic

total = one-off items
      + upgrade
      + Σ (yearly items × (1 + e)ⁿ)
        for n = 0 … 4

Escalation compounds from year two, which is how renewal uplift and currency movement actually behave. No discounting is applied: if your organisation uses a discount rate, apply it afterwards rather than having this tool assume one.

What this cannot price

The cost of an outage this layer would have prevented, which is the whole reason for the purchase and specific to your business.
The value of accumulated tuning, which does not transfer if you change product.
What you lose in negotiating position by concentrating more of the estate on one supplier.
Support quality, which only becomes visible under pressure.

The five-year cost argument works through the reasoning this tool only adds up.