My point is, for most US based (small) ISPs, the cost of transit is about 35-50% of the monthly cost they charge the customer.
Incidentally, there's another greedy, money grubbing monopolist that builds their pricing model around limiting the cost of the good they sell to 35-50% of what they sell to you.
I worked for a Burger King franchise for a while, and at our site, the basic Whopper was sold at just under cost. Yes, under; we paid more to make a Whopper than the customer paid us for it. The biggest factor there was the meat patty.
We more than made up for it in the pricing for add-ons, though. Cheese, extra tomatoes, and bacon easily jacked the price up into profitability. Fries are also amazingly cheap, and so the profit margin on them is fairly significant.
However, the biggest money-maker by far were the drinks. Of the parts that go into serving a drink (syrup, water, CO2, paper cups, straws, lids), the most expensive part per cup was actually the paper cup itself, which cost only a few pennies each. The cost for a drink was only a small fraction of the price, making them almost pure profit.
That is why fast food workers are trained and encouraged so much to up-sell drinks with each sale, whether they know it or not. It's also why the more friendly franchises (of any fast food chain) offer free refills. It's a tiny cut to their margins that sometimes results in a significant boost to their sales. (Often, such locations also allow you to bring in a cup from their chain and get a free "refill", even at a different visit.)
There are plenty of regulations for this area of business, but they are mostly local, so each location is on a "fair playing field" with their local competition, instead of having federal regulations that force them to compete with other locations across the country. (That's not to say that there aren't federal regs; there are.)