.50 would still be far cheaper than most places in the world.
They have union issues which are an obvious problem but the real problems have come from congress like the ridiculous obligation to fund employee retirements something like 30 years into the future.
Frankly I don’t see how they can do it so cheaply. Try walking into FedEx or UPS and ask them to send a letter for 50 cents, and see what kind of a reaction you get.