[Nathan2055]

No, it’s so much worse than that. Look closely at https://aws.amazon.com/vpc/pricing/ and note this line:

> You also incur standard AWS data transfer charges for all data transferred via the NAT gateway.

Yes, the $0.045/GB “data processing” charge is in addition to the usual $0.09/GB egress charge. You are paying an effective $0.135/GB for all of your egress, in addition to the $0.045/hr just to keep the NAT gateway running.

And yes, your ingress and even internal-to-AWS traffic is also billed at the $0.045/GB rate. (An example given on the aforementioned page is traffic from an EC2 instance to a same-region S3 bucket, which they note doesn’t generate an egress charge but does generate a NAT processing charge.) As far as I can tell, the only traffic which isn’t billed is traffic routed with internal VPC private IP addresses, which don’t hit the NAT gateway and thus aren’t counted.

There are highly paid AWS consultants who shave literal millions of dollars off of many company’s AWS bills by just setting it up a cheap EC2 box to handle their NAT instead of using the built-in solution. Doing that instantly wipes out the ingress charges and effectively halves the egress charges, and it’s probably a lower hourly cost than they’re already paying: an a1.large is $0.051/hr on-demand but that immediately drops to just $0.032/hr with a 1 year no upfront reserved plan. If you’re willing to pay upfront and/or sign a longer contract, you can get it as low as $0.019/hr.