2012, there is no such thing as free luggage, the airlines are not to be trusted.
SpiritAir.com is the champion, I hear many people scream,
"I will never fly SpiritAir.com again."
Another person arrived from the USA yesterday; he paid 170 USD one-way, and another 150 for luggage. I am getting bored with listening to people, the number of people angry at SpiritAir.com is staggering.
Please Budget 150 Dollars for Your Airline Luggage One-Way
If one of your friends ask,
"How much does a plane ticket cost?"
I suppose you could point them to Kayak.com, then say,
"Add 300 USD to the price quoted for luggage."
Then, if they are buying a one-way plane ticket, reduce it down to 150, and they will say,
"You was wrong I only paid 80."
And you can relax, knowing people are happy enough when they pay less than what you advised. There is an interesting thing about luggage fees, for some odd reasons, the majority of people ignore, or believe the luggage rules do not apply to them.
But they do...