[ghaff]

For all the (somewhat legitimate) cracks about airline add-on fees for things like checked baggage (for non-status flyers), airlines are actually one of the better travel categories in terms of fully disclosing costs up front. Hotels and car rentals generally will before you press the confirm button but often don't up-front--and this makes comparison shopping difficult because the patterns aren't consistent.

[arcticbull]

Definitely, because they were super forced by the DOT under 49 U.S. Code § 41712. [1,2,3]

[edit to include text:]

  The Department considers any advertising or solicitation by a direct air carrier [...] that states a price for such air transportation [...] to be an unfair and deceptive practice in violation of 49 U.S.C. 41712, unless the price stated is the entire price to be paid by the customer to the carrier...

  [...] Although charges included within the single total price listed (e.g., government taxes) may be stated separately or through links or “pop ups” on websites that display the total price, such charges may not be false or misleading, may not be displayed prominently, may not be presented in the same or larger size as the total price, and must provide cost information on a per passenger basis that accurately reflects the cost of the item covered by the charge.

[1] https://en.wikipedia.org/wiki/Transparent_Airfares_Act_of_20...

[2] https://www.law.cornell.edu/uscode/text/49/41712

[3] https://www.law.cornell.edu/cfr/text/14/399.84