Christie's recently had an auction of a private collection with 16 photos by HN. Virtually all of them fetched a huge premium over their estimates. I guess that would make Helmut Newton way more profitable than the S&P 500
Bergstrøm over Paris went for an incredible 6 times what it was initally valued at:

And the priciest of the lot, Sie Kommen, Paris (Naked and Dressed) went for 60k more than the upper end of its estimate - a full 33%.

Other shots:
Central Park West

Tied-up Torso, Ramatuelle

Elsa Peretti in a 'Bunny Costume'

Christie's sale 2113 - Photographs from the collection of Gert Elfering