NEW YORK (CBSNewYork/AP) — An art dealer’s $15,000 to buy the contents of a New Jersey storage locker filled with paintings turned out to be an amazing deal.

The New York Post reports David Killen found half a dozen paintings believed to be done by Dutch American artist Willem de Kooning, whose abstract paintings have sold for millions of dollars at auction.

Killen bought the contents of the Ho-Ho-Kus, New Jersey, locker last year.

The paintings were originally from the studio of art conservator Orrin Riley, who died in 1986, and his partner, Susanne Schnitzer, who died in 2009.

The paintings aren’t signed, but Killen reached out to an expert who’s confident they were done by de Kooning, an abstract expressionist from the Netherlands who moved to the United States and died in 1997.