We're working on making that page easier to parse, and the fact that you just ran into this confusion reinforces our committment to fix it - thank you!
Amazon has made contributions to open source in many ways, including bug fixes, spending hundreds of thousands/year to sponsor conferences, and even giving the PostgreSQL community a free testing account to run regression, soak, or functionality test suites on AWS for free. So yes, Amazon contributes cash to open source projects, at least to PostgreSQL, which we find to be a wonderful community that we are proud to be part of.
It is true that Amazon Aurora is not limited by the bandwidth of the storage system, as it is huge and distributed across hundreds/thousands of nodes across an entire AWS region. And storage for each database instance is indeed only limited to 64TB, far above what most people need. But each single instance can still have limitations, such as CPU horsepower, memory, etc. The r4.16xl has 25Gbit networking, as opposed to the r4.8xl, which has 10Gbit network. So if your workload is write-intensive, such as streaming or IOT data, you will find the r4.16xl can have significantly better write performance. https://aws.amazon.com/ec2/instance-types/ I hope this helps!
I'm sorry the product team never got back to you. We'll get back to the email you just sent us on the preview thread.
If you have any issues with your bill, let us know and we'll happily look into it. But I'd rather work with you to figure out what went on and get it fixed for you!
@omarforgotpwd, @purphase, @tengbretson: We're working on everything you just asked for - thanks for letting us know they are important!
@jsmeaton: Which region?
On https://aws.amazon.com/rds/aurora/pricing/, if you go to the "PostgreSQL Compatible" dropdown, you will see those same four regions.
We're working on making that page easier to parse, and the fact that you just ran into this confusion reinforces our committment to fix it - thank you!