That is exactly the supply and demand equation that determines track rent. Two stories.

I was up in Portland for the Rose Cup an few years back and the RE of NW region was telling me about a regional they put on for 25 cars. I asked how they afforded that and he said it was a park and the rent was something like $1000.

Years before that I was at a national convention in Baltimore and there was a panel discussion on region track relations. One of the panelists was Jim Haynes, I think Jim was working for Road America then but he might have still been at Lime Rock. He was asked how tracks decided how much to charge for rent. He said he thinks about what a club can get for car count, what the entry fee will be, leaves the region a little profit and charges the rest for rent.