Rex Real Estate Exchange has secured $15 million in Series B funding. The Woodland Hills company, an online agency that sells homes without using MLS listings, said it grew 300 percent last year and has plans for further growth this year. The company has raised a total of $30 million, mostly from big-name investors including Scott McNealy, co-founder and former chief executive of Sun Microsystems; Dick Schulze, founder of Best Buy; Gordon Segal, founder of Crate and Barrel; Amit Singhal, former senior vice president at Google; and Jack Greenberg, former chief executive at McDonald’s. “Our all-star investors and world class management team are deeply committed to improving the real estate industry,” Jack Ryan, Rex’s chief executive, said in a statement. “We are proud to have built a service that puts massive amounts of money back into the pockets of the consumer.” Rex’s business model provides a digital alternative for selling homes. It is a fully licensed brokerage and charges a 2-percent flat fee rather than the traditional industry standard 5 to 6 percent while avoiding the costs associated with the Multiple Listing Service, according to the company.