Greater Des Moines real estate agents wrote 783 contracts to sell houses in January, a 32 percent from December and a slight increase from the 769 contracts that were signed in January 2013, the Des Moines Area Association of Realtors said. Fewer houses actually sold last month, with 482 contracts sold, down from 795 in December and 557 a year ago. Median sale price dropped 13 percent month-to-month to $143,000. That is the same price as January 2013. Active listings dropped to 3,744 last month from 3,765.