Buyers in much of the U.S. paid thousands of dollars below asking prices for homes in September. But negotiating power fell from August, real estate Web site Zillow.com says. Buyers paid 2.9% less, or a median of $6,161 below the listing price on homes in September. That's vs. a 3% discount, or $6,525, in August. Negotiating power peaked in January, as buyers paid 4.5% below list price. They topped asking price in seven areas, most in California