I think in the greater NYC area, there are PLENTY of Mitzvahs year round .. and if you are THE go-to guy, as Marcello appears to be (at least one of them) .. I see no reason to doubt the numbers.
As mentioned, many Mitzvahs are simply about IMAGE.
I know this will come as a shock to most of you, but Cleveland in not just like NYC
But there is a local entertainment company here that does mainly mitvahs, and they start at $10k. A friend was at one that was $45k. They have all kinds of performers, and the dj and or mc is typically nothing special. The overall show is what is special.
And yes it's polished.