Shoppers were left bemused after realising an empty jam jar in a big-name supermarket cost more than a full one.
Customers in Waitrose noticed that a jar of the store's own brand raspberry jam cost half that of an empty jar of the same size - £1.20 instead of £2.50.
Even a jar of well-known Bonne Maman strawberry preserve, also available in the chain, was priced just 15p more than an empty jar, at £2.65.
The items were spotted on sale at a branch of Waitrose in Worcester last week, prompting a flurry of comments on Twitter.
People commented on the social media platform after someone posted a photo of an empty jar of jam available for 29p more than a full jar of Bonne Maman, from 2017, with not much appearing to have changed in 2023.
One Twitter user said: "Clean air is incredibly expensive these days."
Watch: Remove labels from jars with this simple trick
Another wrote: "I re-use an empty Bonne Maman jar every day for overnight oats. Beats me why people buy new jars."
Someone else claimed that buying cheaper jar was about "taking back control".
But one person offered an explanation for the confusing difference in prize.
One said: "Cost of glass is huge - just increased 25%.
"Also, whilst the consumers save money, the brand still has to pay the £0.60 to Waitrose as part of the margin maintained promo."
Another user essentially suggested shopping elsewhere, writing: "27p in Aldi lad."