u/Dull-Mathematician45

I haven't run the experiment, but it appears using ElastiCache serverless I can move data from one AZ to another for $0.0046 / GB, saving 70%. And I can save more by using dedicated instances? Are there hidden cost calculations I'm missing?

This is such a stupid idea, but I'm actually considering it to save costs with a distributed database that ingests a lot of data. Cross-AZ network is 30-40% of my costs. I know people use S3, but I need under 2ms synchronous writes to keep performance and ensure cross-AZ durability. ElastiCache also has 99.99% availability.

Is it true that if move the data myself I pay $0.02, but if I pay AWS to buffer it in ElastiCache for 100ms then it costs $0.0046, and potentially much less?