SAN FRANCISCO, California -- The Bay Area is so expensive, even some six-figure salaries are now considered low income.The Department of Housing and Urban Development just released its 2017 income limits summary. That's the baseline used to determine who can qualify for affordable and subsidized housing programs.For a family of four in San Francisco and San Mateo Counties, $105,000 a year is now considered low income.It's $84,000 in Santa Clara County and in Alameda and Contra Costa Counties, $80,000 is the low-income threshold for a family of four.