Hi Grace:
Maybe in some places that is true. If so, you are correct. But that is only so with things like props, backdrops and the like. Chairs are (at least in most places) consided as "conditional" items". That is, they come with the package.
Think of a cab driver, who rents his cab from company X. Company X rents him the cab and also takes a percentage of his receipts. The cabbie has to pay for gas. This is the usual arrangement. But now Company X also wants to have him pay rent on the tires and headlights?? Nope. When you have rent the cab, your supposed to get the whole cab.
Or.... how about going out to a restaurant for a nice dinner.
You sit down to eat your food. Your server then asks if you'd like silverware for an additional charge.
Huh? Your silverware and that cabbie's tires are "conditional" items. They come with the package.
TV Savannah Center argues that since they are "on the stage during the performance", they are a prop and considers a charge normal. I would say back to them, "I too am on stage during a performance, does that make me a prop also?"
Anyway, the point I am trying to make is, yes there are certain items which should be considered rentals. But others should not be. A venue that does this is not high class by those who have been on stage elsewhere and know a bit about business etiquette. (I am NOT a world travler and have not played in large venues but I have been on a number of stages over the past 40+ years, and have absorbed a bit of experience in this type of thing).