“If it has a Pepsi insert on it, I’m gonna sell it for US$1,000 premium over Coke insert,” said Bob’s Watches COO Carol Altieri, referring to the red and black bezel. “Everybody wants that Pepsi insert.”

It’s somewhat fitting that this model is leading the pack.

Designed as a utilitarian pilot’s watch, Rolex introduced the GMT in 1955 with a dedicated hand to track the 24 hours of the day. The original two-color bezel was red for daylight hours and blue for night, and other colour combos were introduced later.

Switching to a ceramic bezel initially limited the colour options, but 10 years ago, Rolex managed to produce a red ceramic to match the original hue.

Unlike many of the best-performing watches, this particular Pepsi GMT is still in production and can technically still be bought at retail – but good luck finding a dealer who will sell it to you.

What’s more, this watch is selling on the pre-owned market for around US$21,000, or nearly twice its US$10,700 retail price.

“Sellers are a little bit more aggressive. They know that they have something that’s worth a little bit more, so they’re a little bit harder to buy,” Altieri said.

Still, people are buying. Altieri said it typically takes about two weeks to turn over her Rolex inventory, but the Pepsi GMTs turn every two days. “They go a lot faster,” she said.

Altieri also said that the price could be a feature of relatively constrained supply compared with other colours.

“For every Pepsi that comes into the queue, I probably see at least six or seven of the blue and black,” she said.