This past season, its first full one at $10 a pop, the Washington’s Catalyst Theatre performed to an all-time high of 76 percent capacity, and this fall, annual subscriptions have doubled. On a larger scale, though, what Fortier’s daring move taps into is a growing acknowledgment that to attract diverse age groups and income levels, theater and other performing-arts organizations must come up with more radical approaches to pricing that address, among other things, the competition from less expensive nights out.”