"The more you look at the same exact thing, the more the meaning goes away and thebetter and emptier you feel."- Andy Warhol, 1975

If you've ever wondered about the advantages of building a collectibles portfolio, look no further than the results of last night's (May 10) Sotheby's contemporary art sale in New York.

High profile art collectors including Los Angeles financier Eli Broad and the fashion designer Valentino were in attendance to see the United States' favourite 20th century First Lady emerge as the auction's star.

A collection of Pop Artist Andy Warhol's 1964 prints, Sixteen Jackies, left the auction block for $20.24m (£12.4m)plus 12% buyer's premium - nicely above its $20m (£12.2m) pre-sale estimate.

The work dating to 1964 features 16 enlarged images of Jackie taken from news photographs that appeared continually after the assassination of her husband, President John F Kennedy.

Each screen print panel is painted in blue, white and gold.

Sixteen Jackies is based on a series of media photographs taken of America's First Lady on the day of JFK's assassination

Yet here's the thing: rather than viewing a complete Andy Warhol work, prospective buyers were actually looking at a '$20m portfolio'.

The 16 screen printed panels of Jackie were assembled by its seller, in the spirit of Warhol's various other Sixteen Jackies pieces.

In the end, the seller's portfolio approach paid off with the work eventually exceeding its pre-auction estimate.

Overall, Sotheby's New York sale achieved an 84% sale rate. While its experts admitted that some of its estimates were "possibly aggressive," the tactic apparently paid off.

Meanwhile, rival auction house Christie's is preparing to auction another Warhol piece.

Self Portrait (1963-64) by Andy Warhol is going under the hammer with a $20-$30m estimate, also in New York City.