In Contra Costa County in 2018, the number of units sold decreased 6% year over year. Fewer sales could indicate an opportunity for buyers to negotiate better terms. The median sales price was up 7% year-over-year, which is the same trend in most Bay Area counties. Contra Costa County single-family home values went up in 2018, paralleling other nearby counties. The number of new listings trended upward, which is another factor that gives buyers more opportunities.