How I hosted a local television contest for $2.37 on Heroku (mikecoutermarsh.com)

in another words if you had to move beyond the free tier your prices would have gone up significantly.

Would have been free on the AWS free tier but I guess if you work for Heroku, that might be a non starter.

He probably could have hosted it for free on AWS, Azure or even some free shared hosting with PHP and MySQL, too.