Although inventory increased, there were only about 5 weeks of supply for single-family homes and condominiums in Boston's Charlestown neighborhood, according to the Massachusetts Association of Realtors. Homebuyers had just two houses and 18 condos to choose from at the end of January. The median price of a single-family home was $1,326,250, with just two sales in January. The median condo price was $742,000, with four sales