A Banksy-doctored painting sold at an online auction yesterday for $615,000.

It was dropped off at a Housing Works thrift shop near Gramercy Park in New York City on Tuesday morning. The woman who dropped it off said that the painting was of value and that someone would be contacting them shortly, according to the Housing Works organization. So much for an ordinary transaction.

The simple oil painting, titled “The Banality Of The Banality of Evil,” was stripped of its human figure, and now has a Nazi figure painted on, plus the Banksy signature. It is featured on the artist’s website which chronicles his month-long street-art spree all over New York. The original painting was purchased two months ago from the very same thrift shop.

In a thrifty move, Banksy’s people contacted Housing Works, a non-for-profit organization which gives support to HIV/AIDS patients, to authenticate the work and to request that it be auctioned. And as swiftly as Banksy can put up his work, Bidding for Good put the painting up for sale on its online site Tuesday evening. The bidding opened up at $74,000, said the online charity, and closed yesterday at 8pm. After 138 bids, final sale was close to more than half a million dollars. Not bad for a day’s work.

Banksy’s thrift-store move concludes a month long frenzy of action in New York which was documented on his blog, “Better Out Than In.” Street artist Jeff Wong said, “Banksy did a great job of getting people to travel all over the city to places they wouldn’t normally go.” His work was on buildings, inside trucks (he actually staged a working waterfall in one, complete with butterflies), and in parks all over Brooklyn and in the Bronx. ”He got the conversation going about street art,” said Wong.