This 1951 photograph of a purported Yeti footprint was auctioned off at Christie's London for £3,500. Eric Earle Shipton took the photograph in the Himalayas. From the lot description:
'In 1951 Sen Tensing, Shipton, and I descended from the Menlung La ... at about 16,000-17,000 feet we came across a whole series of footprints in the snow, on the lower part of the glacier. There seemed to be two groups, one rather indistinct in outline leading on to the surrounding snowfields. The others were much more distinct with, in places, a markedly individual imprint etched in the 2- to 4-inch covering of snow. We had no means of measuring so after examining them Shipton took four photographs: two of the indistinct prints with myself, my footprints, and rucsac beside them for comparison; the other two photographs were of one of the most detailed and distinct group of prints, with my ice axe for scale, and a second one with my booted foot. The footprint was about the same length as my boot, and I take a size 42 continental, or 8½ British, which is about 12 to 13 inches long. The print was nearly twice as broad as my boot (3 to 4 inches) and had clear-cut edges in the crystalline snow on a base of firm snow ice. There was the definite imprint of a big toe that was broader and shorter than the other rather indistinct toes, of which there seemed to be four or five. We followed these tracks for some way down the easy glacier and noticed that whenever a narrow 6-inch-wide crevasse was crossed there seemed to be claw marks in the snow at the end of the toe imprints. ... Two days later we were joined by Murray and Bourdillon, who, after visiting the Nangpa La ... had followed our route into the Menlung Basin. All tracks had been deformed by the sun and wind.' (Michael Ward, 'Everest 1951: the footprints attributed to the Yeti -- myth and reality', Wilderness and Environmental Medicine, 8, 29-32 (1997)).
Link to Christie's lot, Link to Metro article