I was listening to that "but 20K is a lot of money" and it has puzzled me a bit - PM has a budget. It is a trivial action to tell them in the beginning of the month/sprint/project - "I'm estimating I'll need to work NNN hours this month, so expect a bill of $$$$$". If it is outside of their budget, they would say so and then there are options - scale down hours, reduce the scope, whatnot - without a mutual upset.
I send my estimations to my client at first week of the month, when the scope and the pace becomes clearer, and I yet to hear a single complain for my bills, tho they are sometimes rather large.
Maybe I misunderstood the situation (I was listening while jogging so could have missed nuances), but it seems to me that Andrey played an introvert and did not communicate to the client the consequences of his "working as many hours as you want".