By Quentin Fottrell and AnnaMaria Andriotis

The asking price is the starting point for all home sales, a ballpark figure typically close to what buyers end up paying. But the nation’s real estate market is so out of whack, experts say, that in many cities the gap between the asking and purchase prices has grown enormous. In fact, while home sales are on the decline nationally, list prices keep rising.

Existing single-family home sales fell 2.6% in March from a month earlier to a seasonally adjusted rate of 4.48 million units, according to data released Thursday by the National Association of Realtors. Meanwhile, the median sales price rose to $163,800, up 5% from February and up 2.5% from a year prior. On a national level, the data suggests that individuals who are buying homes are willing to pay more. On a regional level, however, buyers’ offers vary significantly.

In some markets, sellers aren’t getting what they’re asking for or anywhere near it. In the Atlanta metro area, for instance, the median list price was $150,000 in December, according to Realtor.com. But the median sales price was just $90,600 at the end of the year, according to the latest data from the NAR. In Jacksonville, Fla., the median listing price is 34% higher than the median sales price, while in Washington D.C. it’s 13% higher.

It appears these price gaps between asking and actual sales prices continued into March. This week, Realtor.com reported that median list prices rose 5.6% in March from a year prior. Meanwhile, national median sales prices over this period rose just 2.5%, according to the NAR. March marks the beginning of the peak home buying season that stretches through the summer. List prices tend to rise with the temperature, says Julie Reynolds, a spokeswoman for Realtor.com.

Still, experts say asking prices in some cities appear to be way off. When there’s a $50,000 or more difference between the asking and selling price, that’s a sign that the house is likely overpriced, says Mark Goldman, real estate lecturer at San Diego State University’s Corky McMillin Real Estate Center. “Sellers and their agents are more optimistic than the buyers closing on deals,” he says.

For their part, realtors in Atlanta and Washington, D.C., say that the difference is largely due to lagging buyer demand for homes in the suburbs that’s led to homes selling at discounted prices. They say real estate in the city is in high demand and selling near asking prices. In some areas, foreclosure sales, which typically sell at a discount, are pulling selling prices of non-distressed homes down.

SmartMoney crunched the numbers to find the metro areas where the gap between listing prices and the actual purchase prices are the largest and the areas where they’re the smallest:

Most of markets with the highest median year-over-year list price increases in March also experienced the largest reductions in their for-sale inventories and were among the hardest hit by the foreclosure crisis.

Although foreclosed properties continue to account for a high proportion of their overall sales, the four markets with the largest year-over-year increase in median list prices –Phoenix AZ, Miami FL, Boise City ID, and Punta Gorda FL- now appear to be into the recovery process as their list prices are on the increase, according to the Realtor.com Real Estate Trend Data report for March.

The total US for-sale inventory in March 2012 was down by -21.48 percent compared to March 2011, declining in all but two of the 146 markets covered by Realtor.com. The median age of the inventory fell by -19.82 percent on a year-over-year basis and the median national list price was up by 5.56 percent.

“These positive indicators contrast with the situation at the beginning of the 2011 home buying season, when the median list price was down by -4.81% on an annual basis and the age of the inventory was up by 26.14 percent. If the market continues to hold its own, 2012 could confirm the beginning of a broad-based housing recovery,” the report said.

While some of the hardest hit markets — Las Vegas and many parts of California – still lag, markets that didn’t experience the dramatic run-up in housing values preceding the housing crisis- Chicago and Philadelphia– now exhibit persistent signs of weakness. These patterns suggest the nature of the country’s housing challenges have fundamentally changed, and conditions once attributed to the decline of the housing boom now primarily reflect weaknesses in local economies.

The nationwide median list price for single family homes, condos, townhomes and co-ops was $189,900 in March 2012, up from $188,000 in February 2012 and 5.56 percent higher compared to a year ago. At the same time last year-the beginning of the 2011 home buying season–the median national list price was $179,900, 4.81 percent below the median list price in March 2010. While higher list prices don’t always translate into higher sales prices, they can signal a growing optimism on the part of sellers about their local market conditions and buyer demand.

The national for-sale inventory was up by 1.45 percent in March compared to February, a largely seasonal effect associated with the start of the spring home buying season. On a year-over-year basis, the total number of listings was down by -21.48 percent in March 2012, another positive sign that the overall market is in a stronger position than it was one year ago.

The median age of the inventory of for sale listings was 89 days in March 2012, down from 111 days in February and -19.82 percent below the median age in March 2011. While the monthly reduction in the age of the inventory is seasonal in nature, the year-over-year decline in the median age of the total for-sale inventory is consistent with a significantly stronger market heading into the 2012 home buying season. Last year at this time, the median age of the inventory was up by 26.14 percent on an annual basis.

In March 2012, the median list price was up by 1% or more on an annual basis in the majority (111 MSAs) of the 146 MSAs monitored by Realtor.com, and up year-over-year by 5 percent or more in 70 MSAs. The median list price was down by -1 percent or more in 17 markets on a year-over-year basis, with only 2 markets registering declines of -5 percent or more. The remaining 18 markets haven’t experienced a significant change in median list prices compared to a year ago. These statistics represent a steady and significant year-over-year improvement in median list prices in the majority of markets monitored by Realtor.com since the onset of the 2011 home buying season. While higher listing prices may not necessarily translate into higher sales prices, these data suggest a growing optimism on the part of sellers that the market is beginning to turn around.

Five of the ten markets with the largest year-over-year increases in median list price in March 2012 are in Florida. Phoenix-Mesa, Washington DC, and Boise, ID also appear on the list of top 10 MSAs with the largest year-over-year increases in media list prices for March 2012. The relatively large increases in the median list price in most Florida markets compared to one year ago suggest that these hard-hit areas may have reached bottom and are now into the recovery mode. However, the large shadow inventory of potential foreclosures in the state could easily undermine the nascent recovery process.

In contrast to Florida, median list prices continue to be down on a year-over-year basis initially hard-hit areas, including Las Vegas and many parts of California. However, markets that never experienced a rapid run-up in housing prices are now registering among the highest rates of list price declines. This pattern suggests a shift in both the nature and location of the nation’s housing problems-away from the sand states and into older, more industrialized areas that are experiencing the brunt of the economic downturn. The ten markets with the largest year-over-year list price declines in March are shown below.

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