Except at the airlines, the FAA and goverernment (over)regulation.
It just occurred to me that I had heard little snippets about paying fees at the airport for checked baggage (what can I say, I don't get out much, nor do I pay attention to the "news") and that I better find out more about that before heading to the airport next week. So I checked United's website. Sure enough, before August 18 (we leave the 13th)the first bag is free and the second is $25. After the 18 (we'll come back home on the 22nd) the first bag is $15 and the second is $25. Rats. Rats, and $#@%* and rmfabrgleschnigafrigga. It's bad enough that we have to buy water. Now we have to pay for luggage! ARG! What a crock.
I always go with extra bag space and come back with stuff from my parent's house (Mom saves the boy's clothes for Jonah, so I always get the next size when I'm there) to save on shipping it all here. And I know, even with the luggage rates, you can't ship a box for that price. But still. The plane tickets are expensive enough! Then we have to pay for parking and luggage and water and food.