A Sheffield man who collects rare banknotes and coins says South Yorkshire people can make plenty of money as Britain makes the switch to polymer currency.
They just have to put in the leg work, or have plenty of luck, to get the serial numbers required to drive the value up.
Intake man Carl Jones has already collected three of the new £10 notes featuring author Jane Austen.
They are from the first run, and feature the AA serial number, with the year of her birth, 1817.
One of them even ends in the age she was when she died: 41.
He has the note before that, too, with the previous serial number.
Carl, 36, was desperate to bag one of the early Austen notes when they were released that he lined up for hours at the Bank of London on the day.
“I’m in the Sun’s video, in the queue,” he said.
Carl began collecting last year, when a friend told him how much the new £5 notes were selling for on eBay.
“They are going for between £20 and £30,” he said.
“It depends when you strike, really.”
He set out to find a note with an AA01 serial number, and soon found himself engrossed in the hobby.
His collection now includes one of the first ever £5 notes, released in 1949, as well as four commemorative 50 pence coins featuring Kew Gardens.
He spent hours trawling through large amounts of money in the search for those coins.
Carl would withdraw about £3000 at a time - a total of 6,000 coins - to search through.
“An ordinary car feels like an armoured car or a tank when you’ve got that much money in it,” he said.
Carl estimates his collection is worth more than £7,000, but he won’t sell it any time soon.
He plans to one day pass on the collection to his children, three-year-old Estelle and Robin, 1.
“It will be their inheritance,” he said.
“Even if you said you’d give me £10,000, I wouldn’t take it.”
His tips for anyone thinking about looking for rare notes and coins are to never give up.
“You’ve got to put in a lot of legwork, or be incredibly lucky on the internet,” he said.
“The quickest way is to go on eBay and search for consecutive serial number bank notes.”
The new polymer £20 note will be released in 2020.
“When the £20 comes out, to have it, the £5 and the £10, would be brilliant,” he said.
Not everyone in the family are fans of Carl’s hobby.
“My partner thinks I’m crazy,” he said.
“She’s from Slovenia, and doesn’t understand the obsession.
“But I only started last October, and already I feel like I’ve turned into a professional.”