First-time home buyers are taking advantage of the housing downturn and federal housing tax credit to jump into the market.

According to statistics released today by the National Association of Realtors (NAR), first-time home buyers represented half of all existing-home purchases in 2009’s first quarter. Overall, existing-home sales hit a seasonally adjusted annual rate of 4.59 million units during the quarter. Compared to the previous quarter, that represents a 3.2% dip. Such numbers also lag 6.8% behind existing-home sales activity on a year-over-year basis.

NAR Chief Economist Lawrence Yun said he expects such numbers to improve in future quarters. “Over the past couple months, contract activity for home sales, buyer traffic and inquiries about the $8,000 tax credit have all increased,” he said. “Close to 455,000 buyers purchased their first home during the first quarter, and those are likely just the first wave of new buyers coming into the market – they’re critical for a housing recovery.”

Pricing trends remain messy, however.  Many buyers are taking advantage of falling prices, pushing the median existing-home price in 2009’s first quarter down 13.8% on a yearly basis to $169,000, but not every home is priced at—or selling for—rock-bottom figures. That makes evaluating the current state of home values difficult at best, especially in troubled markets.

“In areas with the biggest price declines, we also see much higher levels of distressed sales which are distorting the data,” Yun said. “We are very much in a bifurcated market with sharp differences between foreclosures and short sales on one hand, and traditional homes on the other. In many cases, homes are selling below replacement construction costs, which speaks to great value in the current market.”

Alison Rice is senior editor, online, at BUILDER magazine.