A lettuce "black market" is forming amid a national shortage in which supermarkets are rationing the amount of salad and vegetables customers can buy.
Yesterday Tesco and Morrisons launched a crackdown preventing customers from buying more than three iceberg lettuces at a time after their supply was cut by 80pc due to storms in Spain where they are grown.
But despite the ban market sellers have been caught flogging them for up to 10 times the usual price, with one man selling a box of iceberg lettuce, which would usually cost £5, on Gumtree for £50.
The seller, who lists his location as Acocks Green, Birmingham, urges shoppers to beat the "national shortage" by snapping up his fresh veg.
Going by the name of "Dave", he claims the box of 12 lettuce were "freshly picked today" (February 3) and have a higher price because of "supply and demand".
The lettuce work out at £4.16 each, and his post reads: "A box of a dozen Iceberg lettuce, freshly picked this morning."
"There are a national shortage of these beauties so the price is a little higher due to supply and demand."
Another woman took to Twitter claiming she had a car boot full of lettuces and was willing to offer "reasonable prices".
And it appears lettuces are - quite literally - the tip of the iceberg as other affected vegetables are also selling for ludicrous prices.
Brocolli, which is experiencing a shortage was found being sold for £5 per kg at a London Market.
Courgettes, popular among health-conscious consumers who have caught onto the UK's "spiralizing" craze, were also found selling for an extortionate £6 per kg.
According to the British Leafy Salad Association most market traders are now selling iceberg lettuces for three times their usual price. This is because they are buying wholesale trays for £15 instead of £5.
Prime Minister Theresa May's spokesman said the Department for Environment, Food and Rural Affairs (Defra) was keeping a watch on what was happening.
He said: "Clearly, there is a situation with bad weather on the continent affecting some vegetable crops. "Clearly, supermarkets are working hard to rectify any supply chain problems.
"They are confident that will be resolved swiftly, but the relevant department, Defra, is monitoring the situation," he told a regular Westminster briefing.
Asked how Brexit would impact on such situations, he said: "The rural industry of the United Kingdom will be an area that will come back under our control once we have left the European Union."