I'd imagine it has to be immense. Most of the engineers I know are spending $200/day, let's say 20 workdays per month, $4000/mo. Whatever % of revenue it is, it's got to be close to 100% of profit.
I can't imagine why anyone would need almost 7x that.
But $200/day is very common in the business. The monthly plans are just a trial version of what's going to come for all of us. That's why I am very carefully looking into the open models today.