Ever want the airline-branded pajamas included the hefty price of a first-class cabin without actually buying a first-class ticket? A few airlines do just that — selling first-class amenities to interested coach passengers.

Etihad sells its economy-class passengers the same style of Christian Lacroix sleep suits available in first class for $35 a pair — which, on an ultra-long-haul flight in economy, may make your journey a tad more bearable.

Etihad also makes its business-class lounges and elegant first-class clubs (excluding spa treatments) available for a price. The Abu Dhabi lounges go for $200 a person for two hours. Also available as in-flight purchases are premium amenity kits, Piper-Heidsieck Cuvee Brut Champagne and artisan iced coffee.

Other airlines that allow economy passengers to purchase in-flight business-class meals include Air France, Austrian Airlines and Swiss International Air Lines.

New approaches to selling premium amenities — raising revenue for the airlines — target business travelers expensing trips and meals with their company. Other segments that respond favorably are older leisure travelers and millennials, already accustomed to purchasing meals on discount, no-frills carriers.