How did you test ping? Was it just in games? Or did you actually ping various websites? Does ping improve if you are hardwired to the router? What is the router model? Is QoS on? Have you run traceroute to see where the packets may be getting dropped?

There’s lots of costs to AWS. They’ll rope you in with the whole free tier for compute and storage. But AWS has charges for outbound traffic, detailed logging, elastic IPs, etc.

It’s a whole job to just do cost analysis for cloud services.