Spirit's Reply
I wrote to Spirit with the question, and here is their reply:
Dear Mr......
Thank you for contacting Spirit Airlines.
Fares purchased at the airport are not assessed the Passenger Usage Fee. As a result, it is possible the total fare may be less at the airport.
Please note, however, that our agents do not have access to web-based or $9 Fare Club fares.
Please feel free to contact me with any further questions or concerns.
Sincerely,
Mark 62605
Corporate Consumer Relations
Spirit Airlines, Inc.