In Austin, civic leaders are banking on the idea that a dramatic new performing arts center slated to open in 2006 will secure the city’s performing arts scene for decades to come. But the PAC has to get built first, and supporters are finding that that’s no easy task in the current economy. The hall is expected to cost $110 million, and the city only has $62 million in hand, forcing organizers to move to a phased building plan which will not alleviate the city’s performing space crunch anytime soon. Still, the PAC will eventually allow the city’s arts groups to perform in a top-notch space at relatively low cost.