They don't know in advance how much bandwidth will you use, how much traffic will you have, what auto-scaling rule will it trigger, etc. It's not obfuscation, it's billing based on your usage. And as with everything in life, there are tradeoffs.
Sure, but providing estimated costs based on reasonable pricing buckets alongside the options to add the new machine is something that every other vendor manages to do..
Now explain why they don't have a killswitch for a user defined spending limit.
Price simulators are fine. They also know the distribution of use. They can do cost plus pricing (many cloud providers do). You're defending deliberately obfuscated pricing when it need not be obfuscated.
Give me a slider for bandwidth used or a formula where the variables are abstracted away. If a computer can tell me how much I owe, a computer can be made to show how it came to it’s conclusion.