The New York Post featured an ad for Supreme on its front page on Monday.

Supreme fans are paying $20 or more for a copy of the paper, which typically costs $1.50.

The sportswear brand has gained a cult following as well as mainstream backing. A $500 million cash infusion in 2017 valued Supreme at $1 billion.

Some people are apparently willing to do whatever it takes to get their hands on a copy of The New York Post that has been remade into a Supreme ad.

On Monday, people picking up a copy of The Post would have realized the New York City tabloid had a different look from the usual. The paper featured a wrap-around ad for fashion brand Supreme, the first time The New York Post had premiered such an advertisement for any brand.

Supreme fans quickly snatched up the paper at newsstands and bodegas across the city. Jesse Angelo, The Post's publisher, told the New York Times that Monday's papers "were flying off the shelves."

Now, savvy buyers are already reselling their copies of the paper at a markup.

Typically, a copy of the New York Post costs $1.50. But, this potential collectors' item is selling for much more.

A copy of the paper on eBay. eBay/ericw10291

As of noon ET, one eBay seller had already sold 31 copies for $19.99 a copy. Dozens of other sellers are hawking their own copies of the paper: five for $85, one copy plus a letter to retailers for $50, and copies for less than $10 that quickly sold.

Copies have also flooded fashion resale website Grailed, where they were priced between $7 and $15. A truly dedicated fan could buy 20 copies for $150.

Supreme has gained a cult following since being founded as a skater-centric brand in 1994. In recent years, it has transformed into a mainstream teen obsession, ranking as the seventh most desirable brand for upper-income teens in Piper Jaffray's spring 2018 survey. In 2017, Supreme received a roughly $500 million cash infusion from The Carlyle Group, which valued the apparel brand at $1 billion.