I got the numbers from the fare breakdown, but with ATL airport a 67-mile roundtrip against some nasty traffic knots and a not-so-great situation at the counter once you get there (they're understaffed and seemingly always overwhelmed by people in line trying to check bags, etc.) I haven't tried the buy-at-the-airport approach, so I don't know if the $8.99 could be saved. People in smaller cities or closer to the airport would have an easier situation.

They're basically following the TicketMaster model, i.e. treating convenience in the computer age as something you should pay extra for even though it'd cost THEM a lot more to go back to the old way of selling. TicketMaster gets away with it because they're effectively a monopoly, whereas with Spirit the junk fee is intended to set a floor most of the time on the lowest the customer could possibly (usually) pay, just like "resort fees" do for hotels in places like Las Vegas.

If more people like FTers get wise and start going to the airport and buying they'll just come up with another junk fee, but maybe with the status quo it's another case of being part of only a tiny percentage who'll game the system. I've been in that situation a lot over all these years, which is why I say more power to those who can jump through the loophole.^ Though even the $68 full freight on a RT like ATL-LAS is OK by some.