Ballantyne Housing Market Update/Video: May 2019. Average Ballantyne home sale prices increased slightly in May. Despite an increase in average and median days on market, homes continue to sell in under two months, on average. Pending sales were up 11.2% in May. The months supply of homes at 2 months and a 16.8% drop in housing inventory keeps the Ballantyne/28277 zip code housing market a seller’s market.