Launched a free tool https://aws-calculator.com today.
I wanted to focus on the most queried service of AWS (EC2) but also wanted to include my personal pain-point - getting fargate pricing.
Posted on reddit and the reception seems to be good https://www.reddit.com/r/aws/comments/fr4i4t/inprogress_aws_pricing_calculator/
It seems the two biggest tasks would be differentiating it from the other 2 calculators provided by aws & making it more feature complete without compromising its ease of use.