(CNN) — There are many urges that fliers have to contend with while cooped up on a plane at 35,000 feet, but procuring a rare blue diamond typically isn't one of them.
For the wealthy few who do need to splash cash on high-end jewels though, it's now possible.
The catch: It's only possible if they're flying Etihad's top-tier route from London to Abu Dhabi.
In what some in the aviation industry have dismissed as a superficial gimmick, the UAE-based airline has teamed up with an upscale concierge service to cater for the whims of passengers using its luxurious Residence service.
The flight's $20,000 one-way ticket already buys them a three-room suite complete with inflight gourmet chef and a butler.
And now they won't have to wait until they land to shop for baubles, grab coveted reservations at Michelin star restaurants or tickets to sold-out shows.
Residence passengers can also instruct the concierges, provided by Ten Group, to hunt down rare handbags or fine art. The service is a far cry from the cheap, cheerful and somewhat random selection of fripperies available in the inflight SkyMall catalog once ubiquitous on U.S. airlines.
As long as it's legal
"As long as it's moral and legal, we offer a whole assortment of weird and wonderful things," says Toby Gauvain, international managing director of Ten Group, which has offices in London, New York, Hong Kong and beyond.
He says he isn't allowed to disclose details of requests received so far, but says the service has proved popular since it launched at the end of August.
Passengers relay their wishes to the on-board butler who then calls Ten Group's concierge teams from a satellite phone.
If it works, everything is in place before the plane reaches its destination.
Bathroom of The Residence three-room suite.
The in-flight concierge is the latest move in what seems to be Etihad's quest to turn its airliners into fully-fledged luxury hotels.
Residence suites have a living room with a 32-inch flat-screen TV, a bedroom with a double bed draped in Egyptian cotton sheets, and a carpeted hallway which leads to an en-suite bathroom with a shower, bathrobes and high-end toiletries.
Etihad says the first person to fly on board The Residence had no complaints.
In fact, the airline's PR machine quoted Gino Bertuccio describing his trip, somewhat improbably, as "beyond anybody's imagination."
"After returning home, I was living again minute by minute this fantastic journey I was lucky to live," he added
"When we launched The Residence by Etihad last year, we wanted to challenge the conventions in commercial air travel," says Peter Baumgartner, Etihad's chief commercial officer. "The Etihad Lifestyle Concierge service is a continuation of that ambition."
Baumgartner says it serves passengers who are stretched for time: "For example, if they were unable to make any preparations before traveling, or need something unexpectedly.
"It also suits passengers who are looking for something out of the ordinary, perhaps a unique gift for a loved one, such as a rare blue diamond, "he says.
Is it a gimmick?
For some airline industry experts, Etihad's latest move is little more than a gimmick.
"Frankly I think the concierge service offered by Etihad is style over substance," says Ben Schlappig, a connoisseur of major airlines' first-class experiences and author of popular aviation blog One Mile at a Time.
"Ultimately I doubt this will be much more valuable than services offered by many top-end credit cards, and likely won't have the local expertise or clout of a top hotel concierge.
"Presumably people dropping $20,000 plus on a one-way ticket already have access to other concierge services," he adds.
But Baumgartner insists that as people travel further and more often, the time spent on the journey needs to be more enjoyable than ever.
"How we travel is changing. Today's tech-driven, fast-paced world means that we have to strive to be innovative, rethink what we've done historically, and offer more convenience and comfort to our guests," he says.