I currently have a WordPress hosted on AWS. My last month's bill was only $6.60. I don't really have a ton of traffic so I imagine that could get more expensive. But AWS was built for scalability!
AWS LightSail starts @ $3.50 / month and is surprisingly easy to set up! I found some pretty easy to follow tutorials online. If you are interested in getting your feet wet within the AWS ecosystem I strongly advise going this route :).
On a side note, AWS also has a service called AWS Fargate which charges you by the resources you need (RAM / CPU). I personally use AWS Elastic Container Service (ECS) to run Fargate "tasks".