Awesome! This question has already 3 answers..
For Amazon AWS proxies you are charged only by Amazon.
Basically CreateProxy.com will create Proxy Servers for you in your own Amazon AWS account, that how it's works.
Price for Amazon depend on selected instance, when you are creating proxies through CreateProxy. You can find Amazon EC2 pricing at this page https://aws.amazon.com/ec2/pricing/on-demand/
Most of users selecting t3.nano which has only 0.5 GiB on RAM, but that is enough for most cases, for this instance you will be charged $0.0052 per Hour. (that's also total price for your proxy server)
So for single Proxy IP you will be charged $0.0052 / hour or $0.0052 * 24 / day.
Also with CreateProxy.com you can create any number of Proxy servers on AWS (only limit is set by Amazon, so you may be able to create only up-to 20 instances at same time) - If you need more instances you can ask Amazon Support for increasing your instance quota, more about limits you can find on this page: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-resource-limits.html
So you can create for example 30 proxy servers (instances) at same time for only few hours, then you can easly remove them with CreateProxy.com and create another 30 proxy servers.. this way you can get every few hours fresh never used Proxy Servers - so basically CreateProxy is managing your instances, that's what it do.
Also you can Add multiple Accounts for Amazaon AWS, same as for other providers, since you can as for now delete all proxies at once for single account - but that's answer on another question.