> 37% off instances still leaves you paying list price for bandwidth, which was 22% of our AWS bill.

This is the most infuriating pain point when using AWS.

We have premium support at work and the engineers basically read the documentation back to us, ignoring our complaints about cross-az bandwidth and the utter and complete lack of az-awareness in their services.

Example: we had some redises that we wanted to migrate to ElastiCache... All the aws engineers did was reading back the marketing pages and pushing for the serverless offering (where bandwidth was the main cost driver). The reader/writer endpoints are totally az-unaware.

Cross-AZ bandwidth for ElastiCache was costing us MORE than ElastiCache itself.

In the end we had to engineer AROUND ElastiCache in order to get it working, and working with predictable pricing.

"Invent and simplify" my ass...