Advertising signs started bringing high prices at the Peter Sidlow sale in 1989. We were there for the auction and featured it on our TV series. The tin Campbell’s Soups American flag sign made between 1905 and 1910 that was bought in 1981 for $3,700, sold for a record at $44,000. That tin sign has been copied in several sizes. There are two antique versions of the sign. One says “Just add hot water and serve” on the bottom with “6 Plates for 10¢” on the top. The other says “Just add a can of hot water and serve” with “21 Kinds” on the top. By 2008 vintage lithographed tin signs were selling for thousands of dollars. A record $100,000 was paid for a Campbell’s Soups flag sign in 2012. Prices for tin sign rarities in good condition are still going up in price, but few have reached $100,000. Good but not rare paper poster size signs sold last week in our “declutter” sale went for $100 to $400. Tin signs sold for at least twice as much.