I already discussed it in this column when it went unsold in 2009 in another auction house. At that time I questioned how to anticipate the price of such a unique piece.
How much may it claim? Some collectors who so much enjoy when the stamps still have their original glue will be frustrated by the need to open the locket for checking this feature (but it is indeed one of only five never hinged specimens). Others will not like the slightly creased corners.
It is now estimated beyond $ 100K which is in line with a private sale which was reported at $ 90K in 2003.
I also told in 2009 why this stamp went into the locket.
The visitor to the post office of Washington DC who acquired and discovered to his own astonishment on May 14, 1918 the unique Inverted Jenny error sheet had already a very good bargain by selling it six days later to a stamp dealer.
The dealer serialized the stamps on the reverse in light pencil from 1 to 100 depending of their position before he separated the sheet.
The next owner who acquired the 100 stamps included the position 9 in a locket, back to back with a normal non-inverted Jenny, and made it a gift to his wife. The photos of the new catalogue (see link above) include both faces.