And the price goes down every day for a week as the pick of the crop is sold.
The National Hereditary Breast Cancer Helpline which will trial the clothing sales by weight scheme from tomorrow - Saturday, March 2 - at its 3,000 sq ft store in High Street, Doncaster, 10am to 5pm.
Prices on the first day will be £15 per kilogram - equivalent to around 10 women's tops - then drops to £10 per kilo on day two, on Monday, then £8 per kilo day three, Tuesday, and £5 per kilo, day four, Wednesday, before a clearance sale on the Thursday.
The store will re-stock on Friday and start again with items at £15 per kilo each Saturday.
It is the idea of the charities founder Wendy Watson, aged 64, of Derbyshire, who founded the charity in 1996 after she became the first woman in the UK to have a pre-emptive mastectomy.
The pre-emptive mastectomy procedure was made famous in 2013 when American actress Angelina Jolie had the surgery.
The National Hereditary Breast Cancer Helpline now runs a network of nine charity shops around the country including Pinstone Street and Ecclesall Road in Sheffield, Howard Street, in Rotherham, Queen Street, in Morley. Leeds.
It's other charity shops are in Matlock, Ilkeston, Derby and Stockport.
But Doncaster is the only one to be trialing the new fundraiser of clothing sales by the kilo.
Wendy, appointed MBE for services to people with breast cancer, launched the charity to raise awareness and fund a phone line where people can speak to her for support and advice.
She says fundraising is vital tokeep informing women of the dangers of breast cancer - adding that in Sheffield there are 7,845 people with a high risk gene fault, half of those due to the well know genes, BRCA 1 & 2.
Doncaster has over 1,500 high risk breast cancer gene faults, she said.
Wendy said; "We believe selling charity clothing by the kilo and reducing the price daily through the week is a UK first.
"In a bid to keep our information centres in the town centre functioning- we are finding an innovative way of charity shop sales.
"There will be around 3,000 items to buy like this in the back half of the store. Customers don't have to buy exactly a kilo, but whatever they bag up will be sold by how much it weighs starting on day one at £15 per kilo.
"A kilo is equivalent to about 10 ladies' tops - so that's a lot for your money.
"We decided to reduce the price substantially every day after that as the pick of the crop is likely to go first. A new week starts again with all fresh items.
"It's being trialed at our biggest charity shop n Doncaster, where the front end will still have higher value items, furniture and such available at individual prices."
HELPLINE: For more information, advice and support call the National Hereditary Breast Cancer Helpline on 01629 813000 or visit www.breastcancergenetics.co.uk.