Does it matter in 2014? Only time it could possibly matter is international calling, and then I'd probably just Skype them whether their number was toll-free or not. So even that hardly matters.
The part I don't get about Spirit is why they want me buying their tickets in person at the airport. That's surely a more expensive way for them to do it, right? The inability to book online (without paying garbage fees) is a major deterrent from me booking Spirit. (In case 28" seats aren't deterrent enough...
) I'm rarely just hangin' out at the airport in the Spirit counter area...