A Puzzle for the Economists

While browsing through the kitchen gadgets in a local department store, I spotted empty jam jars for sale, presumably for people who make their own jam.They cost £1-59 each.

For less than that one can buy similar jars already filled with jam.

Perhaps there is scope for arbitrage - buying jars of jam from a supermarket, eating the jam, and then re-selling the jars at a profit.

I wonder what the economists would say about it.