More than 10,000 postcards, which were collected by one man, Tim Hale, and document the changing face of the city, are set to go under the hammer this Thursday, September 12.
Picture Sheffield, which provides access to the council's extensive photo archives, wants to buy those postcards and preserve them for future generations to appreciate.
It is seeking to raise £1,000 or more by Wednesday so it can snap up at least a part of the collection, which is divided into hundreds of lots that are between them expected to fetch a five figure sum.
The council's archives already contain more than 100,000 photos chronicling Sheffield life from the 1850s to the present day.
But Picture Sheffield believes that collection would be improved by adding Mr Hale's postcards, which record major events including royal visits and the Great Fire of Heeley as well as ordinary street scenes.
Picture Sheffield said: "The outstanding collection captures the changing face of the city in its many aspects over nearly 100 years....
"There are over 10,000 photographs up for sale. We want to buy as many of them as we can so they are preserved for future generations and made available for everyone to enjoy on Picture Sheffield."
See paypal.me/sheffieldArchives to make a donation, ranging from £1 to £50.