Macklemore performs at BottleRock Napa Valley in Napa on May 26, 2017. Alessio Neri/STAFF. Ben “Macklemore” Haggerty doesn’t like to spend $50 on a T-shirt. That much is clear upon listening to “Thrift Shop,” a four-minute ode to the joys of finding a bargain that’s on the Seattle hip-hop…