So this is what I've been told and have read. All ticket brokers are part of one organization. Ever notice that they have the same inventory? They pay the promoters up front for a "chunk" of tickets. This way, the promoters cover the cost of putting on the show. If the show doesn't sell well, they have still covered their cost and eliminate the risk of losing money. They actually make a premium on the tickets. And the brokers make a bigger premium on the buyers. Each broker can charge what they like, but it's usually within a certain profit margin. The Stones have figured out what people will pay and set those prices according. I know it's expensive, but there's enough fans that will pay those face values. Now the broker's prices are above that margin and they will probably end up losing money. So the Stones may be actually helping the situation. These are special shows that are a matter of supply and demand. If they were all $100, they would still be reselling for the same high prices. The fans on a budget will have to wait for the next stadium tour.
Just FYI, many of the "ticket brokers" you are referring to are websites that simply facilitate secondary sales. The actual sellers that have the tickets place the tickets on a number of sites in the hopes of selling them. That is why the inventories sometimes overlap.
The big news here in NY this morning is the shock and horror of "Ticket Scalpers" making big money on the back of the benefit concert.
The mayor has personally asked Stub Hub not to participate in such behavior. Of course this is the mayor who has banned large soft drinks in NY and is working on peanuts and salt. Can't stop the murders on the subway in broad daylight, but no big gulps here.
Good luck Mr. Bloomberg but there is another scalping larceny going on right under your nose in Brooklyn. At least NJ has Chris Christie which means less of a chance of getting whacked while trying to buy that scalped ticket outside the venue.