What 'free' costs
The list price of Kong OSS is zero. The actual cost is the EKS line, the observability stack (Grafana Cloud or self-host), the engineer FTE fraction, and the on-call burden. At a 0.5 FTE allocation, the loaded cost is over $7,000 per month before infra. See /calculator/self-hosted-tco.
When SaaS is the right answer
Small platform team, regulated industry, or buyer who values SLA over per-second flexibility. The SaaS markup is paid for by the FTE you do not hire.