It depends entirely on how a firm has their infrastructure set up - if you have small cluster(s) per client for isolation/compliance purposes, you end up with, for example with 250 clients, each one using, say, 1000 billable hours/month:

250 * 0.1 * 1000 = $25,000/month.

This is quite the price hike for something that was a) free until now. b) Not a service that warrants such a fee given that it uses existing (GCE) resources and can frankly be done manually by one of the DevOps engineers for a few hours/month and some scripting. It's just a charge for convenience it seems.