The median price paid for a house in Southern California rose 23.4% from a year earlier, representing a 56-month high in March, according to San Diego-based DataQuick.

The median sales price for the six-county Southland region was $345,000, up 8% from $320,000 in February and up 23.4% from $280,000 one-year prior.

The previous median high was $348,000 in July 2008.

“Price measures continue to rise for two simple reasons,” said John Walsh, DataQuick president. “First, demand for homes has risen at a time when the available supply is unusually low. Prices have had nowhere to go but up in many areas. Second, the gains are especially high right now because of the change in market mix: Sales of lower-cost homes have fallen at the same time activity in the higher price ranges has risen.”

According to a report by DataQuick, sales of mid- to high-end homes shot up this spring as the impact of foreclosures continued to fade. 

Despite a sharp drop in sub-$300,000 deals, total sales were the highest they’ve been in six years for the month of March. 

A total of 20,581 new and resale houses and condos sold in Los Angeles, Riverside, San Diego, Ventura, San Bernardino and Orange counties last month, DataQuick reported. This marked a 29.1% jump from 15,945 sales in February and a 3.1% increase from 19,953 in March 2012