Made popular by environmentally and socially conscious youth, the practice involves fashion shopping at opportunity shops.

The craze has proven so popular that some charities have altered their stores to cater to the new customers.

The Salvation Army is reporting an 8 per cent increase in sales throughout its 110 stores across the ACT, NSW and Queensland.

The sales spike means the opportunity shop, once the domain of battlers, has had to go up-market to cater to a broader client base.

The popularity prompted a revamp of the Salvos' Fyshwick store, with the grand reopening attracting hoards of bargain hunters yesterday.

The restyled store boasts more space, a department store layout, more products and extra change rooms.

ACT area manager Tony O'Connell has worked for the Salvos for 18 years and watched the shift to customers from broader socioeconomic backgrounds.

The traditional battler clientele now shared the store with the middle class, teenagers and trendsetters.

''The amount of young people we get through, and not just for dress-ups, has increased because opp-shopping is cool,'' Mr O'Connell said.

''Young kids love buying daggy stuff because that's the look.''

Emily Peddle, of Scullin, buys second-hand clothing for its social and environmental benefits. The 24-year-old's funky personal style is testament to her opp-shopping prowess.

''I don't see why you need to buy new things when there's all this stuff here waiting for a new home,'' Ms Peddle said.

''It's recycling, better for the environment, and it's cheaper. Plus your money is going somewhere to help people, rather than into the pockets of a big corporation.''

Amid the changes, Salvos Stores eastern territory general manager Neville Barrett said the charity hasn't forgotten it's traditional customers.

''With rising energy and food prices impacting the community, particularly our senior citizens, this store will have an even wider range of bargain-priced items for sale, including essential new household items such as bathroom and cleaning products,'' Mr Barrett said.

''All profits from Salvos Stores goes towards running important Salvation Army programs, which assist the less fortunate.

''By shopping at and donating to Salvos Stores our customers and donors are also helping the environment by recycling.''