By Wilton Jackson The purchase of the Phoenix-based franchise and the WNBA’s Mercury is expected to come with a hefty price tag. More than two weeks ago, Suns and Mercury owner Robert Sarver announced he was searching for potential bidders in the sale of the Phoenix-based basketball franchises. As the process heats up with potential contenders, one investment bank official believes the sale of the Suns will result in an astronomical price tag, especially considering the influences associated with purchasing the team. “It’ll be the highest price ever paid for an NBA team,” one investment bank o…