I recently had a fun experience with something called the "Fly America Act", a law which says that when the US government is paying for your travel you have to fly on a US flagged airline.

For my trip, the flight would've been about 6 hours (direct!) and cost $600 on a foreign airline. On the cheapest US carrier, the flight was about $850 and took 10 hours due to a layover. When you take hourly rates into account, it easily cost the government an extra $1000 for me to travel on the US airline.

I wish I could've taken the direct foreign flight and just sent United a check for $250. Would've been a win/win for everyone— the American airline gets its corporate welfare without any of the costs they incur when someone actually gets on their plane, and I wouldn't have had to waste 4 hours of my life each way sitting in an airport to satisfy a dumb law.