VALLEY/digestADD/1stjc March sales of existing homes in the San Fernando Valley were up 25 percent over the like period a year ago, and at their highest point in eight years, according to the San Fernando Valley Association of Realtors. “Sales are still heavily concentrated in entry level price ranges, but activity is building in all categories,” said the association’s president Mel Wilson. March single-family home sales rose 33.8 percent from the month before, with 882 sales completed. Home resale prices rose a modest 1.6 percent from 1996, and were 3.2 percent higher than in February, the association found. The median resale price of a single-family home in March was $160,000. “Even if the inventory remains at current low levels, I do not expect to see prices rise quickly,” Wilson said.