This AskAndy thread contains some excellent analysis and brainstorming on the economics of tailoring today. Essentially there are two options: demand stimulation (e.g. better marketing and branding) and supply chain efficiencies (e.g. outsourcing or automation).
An example of both would be Kilgour, which has rebranded itself as a luxury apparel brand and introduced a more affordable bespoke line by pulling a lower cost, skilled workforce from overseas into the traditional production model.