Funds raised will go to the Retail Trust, a charity for retail workers
Online bidders have offered several thousand pounds for the "last" bag of Woolworths pic'n'mix.
Ed Adams, a Woolies store manager, snapped up the pic'n'mix just before his shop in Petts Wood, Bromley, south London, closed for the last time.
Mr Adams is auctioning the sweets to raise funds for Retail Trust, a charity for retail industry workers.
The bag has been officially certified by Woolworths' administrators, Deloitte, as the last one.
The 800g bag includes fizzy cola bottles, rhubarb & custards, strawberry bon bons, Turkish delight, white mice and pineapple cubes.
Bidding started at 99p on 11 February and had reached £350 by Friday afternoon.
Late on Friday night several bids of well over £1,000 had been placed.
"I spotted at least a bag's worth of pic'n'mix was left in the counter just before I closed the shop for the last time," Mr Adams said.
"I then decided to bag it up before contacting Retail Trust to see if it could be auctioned on their behalf."