Home sales in Clark County inched down in April, although the median price — half sold for more, half for less — crept higher. There were 400 closed sales in April, down 2.9 percent from March and a 4.3 percent decline from April 2011, according to Portland-based RMLS. The median price rose in April for the first time in more than four years, rising by $100 to $190,000 from $189,900 the same month last year.WASHINGTON — Americans are buying more homes in every region of the country, the latest indication that the housing market could be on the mend. An increasing portion of those sales are from first-time buyers, who are critical to a housing recovery.Sales of previously occupied homes rose 3.4 percent in April from March to a seasonally adjusted annual rate of 4.62 million, the National Association of Realtors said Tuesday. That nearly matches January’s pace of 4.63 million — the best in two years. It is still well below the nearly 6 million that most economists equate with healthy markets.A pickup in hiring and cheaper mortgages, combined with lower home prices in most markets, has made homebuying more attractive. While many economists acknowledged that the market has a long way to go, most said the April sales report was encouraging.“The trend in sales is upward, and we think it has a good deal further to go over the next few months as payrolls pick up further and mortgage availability improves,” said Ian Shepherdson, chief U.S. economist for High Frequency Economics.