Clark County’s housing market reached an entirely new level last month when the median sale price passed $300,000.The Market Action Report released Thursday by RMLS, a real estate listing service, said August’s median sale price for a single-family home was $307,000.That figure has never been that high — at least going back as far as 2000, RMLS data show. It’s a 5.4 percent increase from July and a 15 percent year-over-year increase. Over the last several months, however, prices have climbed toward $300,000. Since April, the median sale price has been at least $290,000.“I expected to see a little bit slower activity, and we didn’t see that,” said Terry Wollam, managing broker for Wollam & Associates in Vancouver. He said home shopping often slows down in August when people are on vacation.There were 831 closed sales, 877 pending sales and 1,132 new listings in August.New construction, which tends to be costlier, represents a growing portion of local inventory and could be one reason that the median sale price went up, Wollam said. On Thursday, there were no listings on RMLS for available new construction homes in Clark County under $250,000.Low supply in the housing market has bolstered competition among buyers. As soon as inventory becomes available, it gets scooped up or possibly enters a bidding war. That’s reflected in the diminishing amount of days homes spend on the market. In August it was 38 days, in July it was 44 days, and last August it was about two months.