I mostly work in AWS. I was recently creating an environment and a deployment mechanism for a fairly simple app that was initially developed in Azure. The client was surprised because the cost estimates previous devs gave him (based on Azure) were a lot lower. I don't know what their Azure architecture was - I had to come up with AWS stuff from scratch. Maybe they omitted certain things like backup, DR, auto scaling etc from their initial estimate or maybe it is worth looking at Azure. It is not the first time I'm hearing something along the lines of "Azure is cheaper".