Sotheby’s (BID) is gearing up for what could be its biggest auction in history. The vast collection of artwork and sculptures is from billionaire real estate developer and former Sotheby's owner, A. Alfred Taubman, who passed away earlier this year. The auction flaunts paintings from legendary artists like Rothko, Modigliani and Picasso. With 500 pieces in the collection, the auction could be worth over a half a billion dollars. 'The contemporary art that Mr. Taubman collected is exceptional,’ said Alexander Rotter, sr. vice president & co-head of contemporary art worldwide at Sotheby's. ‘It's highlighted by two amazing [Mark] Rothko paintings – one from 1952 and one from 1962. Both of them are expected to sell between $20-$30 million.’ As for who is scooping up paintings with 8-figure price tags -- it all comes back to one thing. 'Everyone who has the money can be a buyer,’ Rotter added. But it's not just paintings from the world's most famous artists. The Taubman collection includes a host of statues and sculptures. 'He collected lots of wonderful sculptures from Jean Arp and Ignazio Jacometti,’ Rotter said. ‘The variety and the scope of his collecting went two dimensional, three dimensional - in every direction.' TheStreet’s Scott Gamm reports from New York.