Most investors are looking to own at least 50 percent of a designer's brand, as Gucci Group did in 2001 when it launched the Stella McCartney fashion house, which is slated to reach breakeven this year, aided partly by licensing pacts and partnership deals with the likes of Adidas, LeSportsac and Target Australia.

"Gucci [Group] has been very good at launching new designers, or relaunching old brands," Ohana noted.

Burke said many young designers get fixated on having majority control. "For an investor, that's not easy," he said.

Most agreed a partnership is the best route, as many of fashion's biggest success stories involve a striking rapport between a designer and a businessperson, with one of the earliest examples being Yves Saint Laurent and Pierre Bergé, who built a landmark French couture house.

"I don't think an investor can afford for a designer not to be implicated," Morgan stressed.

Mallevays cautioned that each brand has to be handled differently. "The most successful and durable partnerships are when brand and operating control are shared, not wholly ceded nor entirely kept by the designer," he explained. "This is not the same as artistic control, which should remain firmly within the designer's camp."

Observers noted start-ups are done at higher risks and higher costs — with flagships and big marketing — or with less working capital by outsourcing production and doing purely wholesale distribution. "That's how a lot of great businesses got started," Halpern said, adding the latter strategy can take a long time.

In Halpern's estimation, it is probably harder for designers to find backers today than in the Eighties or Nineties, despite a market flush with investment capital.

"The market is bigger, but on the other hand, it's far more competitive, and the large luxury conglomerates exert more powerful control over distribution," Halpern noted. "It's harder to get noticed."

But the promise of finding the next Bottega Veneta, Dolce & Gabbana or Jimmy Choo is what fuels speculative plays, where the odds of success are low, but the payoff can be massive.

"It's a little bit like backing a rock star," Halpern said. "If they're big, they can get really big."