Chicago Lyrica Opera used to sell out most performances. Now it sells 90 percent of its seats. Still good. But. “To help stop any further erosion and, at the same time, reward its longtime subscribers, the Lyric is coupling its announcement of repertory and casts for its 2006-07 season with the news that it also is freezing subscription prices next season. That’s the good news. The bad news, for single-ticket buyers, is that the company (which has an operating budget of $58.2 million) is raising single ticket prices by about 3 percent.”