The Maine Association of Realtors says sales of existing single-family homes in Maine jumped 8 percent in March from a year ago, while the median price increased 6 percent. The association says real estate agents sold 792 homes in March, up from 731 in March 2012. The median price was $170,000. For the first three months of the year, existing home sales rose nearly 8 percent, with the price going up by nearly 5 percent. Cumberland County had the highest median sales price from January through March, at $219,000. Piscataquis County had the lowest median price, at $60,000.