Investors and first-time buyers dominate home purchases in Las Vegas, and their investments will be key to burning foreclosure inventory, a research company reported. Almost 70 percent of the area homes and condos sold in July were foreclosure sales, meaning those homes had been foreclosed in the past 12 months, said Andrew LePage, a spokesman for MDA DataQuick, a San Diego research firm. July’s percentage of foreclosure sales was the same as June, but up from 62.5 percent in July 2008.