Mildred Block had a fine run at Shea Stadium, staffing a lucrative beer stand in a prime location near the right-field cheap seats during Mets games. She averaged $40 per night in tips. The 85-year-old Block had worked the stand for nearly 20 years. But then late in the 2008 season, concession operator Aramark sent Block down to the equivalent of the minor leagues: a booth where she pockets far fewer tips.