As you can deduce from recent articles, I’m playing with the AWS price list. The research is about decomposing the cost into infrastructure, os costs and software cost.
During the research I came across a negative value for a software cost. From my data it seems that in certain regions, the r4.2xlarge with Windows AND SQL Server Web, costs less than the same instance without SQL Server Web.
So I did a fast check with the AWS Simple calculator (great tool) and voila
It is confirmed and r4.2xl with SQL Server Web costs less than one without SQL Server Web installed.
My guess is that this is a human error
Great results for AWS possible errors on 7 rows out of 27001, so a 0.0259249657% error