Rayoflight,
I think that the thing that factors into the most of not everyone willing to pay top dollar for a ticket is this. That you can find a discount code if you know where to look for it. That is the key phrase here. Because your average tourist doesn't know where to go for the discount codes. So, they assume that the telecharge/ticketmaster offering for 100 bucks for a ticket is the only way to get good seats.
Also, many tourists are in the mindset that yes, Broadway is expensive. But, they never really know how expensive it is. So, when they are going to their hotel ticket desk to get tickets for a show. They don't really wine and moan so much when they hear that they have to pay an arm and a leg for a ticket.
"If you try to shag my husband while I am still alive, I will shove the art of motorcycle maintenance up your rancid little Cu**. That's a good dear"
Tom Stoppard's Rock N Roll