A New York City landlord who plastered over a Banksy mural is likely regretting that decision amid reports that a U.S. gallery is planning to auction off a work by the street artist that was recently cut from the wall of a London building.

The Miami gallery is estimating that the 2012 Banksy mural, now called “Slave Labor (Bunting Boy),” will fetch between $500,000-700,000 at auction this Saturday. The work was removed last week from the side of a department store, apparently with the approval of the building owner.

The removal of the high-profile artwork has enraged residents of the North London neighborhood where the piece had become a tourist attraction since appearing last May on the side of a Poundland dollar store. The owner of Fine Art Auctions Miami has declined to identify the collector who has consigned the 48” x 60” mural for sale.

The looming six-figure windfall--for a piece of public art--could prompt a run on other works that Banksy has created. 

However, one of the mysterious artist’s works will never find its way to the auction block. Known as “Bronco Boy,” the mural appeared several years ago on the side of an East Harlem apartment building (though when a photo of the piece appeared on Bansky’s web site, it was described as having been done in the Bronx).

The owners of the uptown building, however, apparently were unaware that they were hosting a rare Banksy mural. As seen in the above before and after photos, the artwork was subsequently plastered and painted over, likely mistaken for the handiwork of a neighborhood graffiti aficionado.

Calls to Solomon Gottlieb, an officer with the Brooklyn-based company that owns the Harlem property, were not returned.