Seriously, I don't think you guys realise how tight the margins are for many bands, and how little money is in touring. Many bands tour at a loss out of passion or in the hope future tours will be more profitable, or tour to break even. A couple of good or bad nights can make or break the tour. Or one shitty venue that doesn't pass on your share of the door/bar takings (either at all, or in a timely fashion) can break your tour.
Your main expenses are travel, accommodation, and food, though you eat like shit and stay on somebody's floor as much as possible (I have mates who are often putting up touring musicians). Maybe after one show you do well and can split the $200 profit between the band members and crew so that you can eat something nicer than McDonald's today. Oh, wait, that went on the visa? Better just go through the drive-thru on the way to the next show then. Obviously this US increase isn't as bad as it first appeared, but you can't suggest $100 is not really that much.
Plenty of Australian bands when they tour North America or Europe hold hometown fundraising shows to offset some of the costs. I've spoken to a few whose US tours were planned in the hope of breaking even (not always successfully) and that they would get enough exposure to do a profitable tour later. For some that worked. Others spent months paying off their debts - or maybe still are.