A lot of people really hate the idea of tickets being sold on the secondary market. The bottom line, though, is that this is naked capitalism on display. If someone wishes to sell a ticket to a hot show, market forces will take over and ultimately settle at their true value.
The goal for anyone shopping for tickets this way is to time the market. You can buy now, pay more and secure your ticket. Or you test your nerve and wait until the last second to drop the hammer.
Cameron Gordon at Completely Ignored has created this graphic showing the current prices (as of July 20, 2018) of tickets for shows at the Danforth Music Hall in Toronto between now and December. Click on the image to see the whole thing.