Box seats at Fenway for opening day are going for $250 in the secondary market, 1/2 last years' price. Grandstand seats are going for $150, $100 below a rear ago. There is interesting information on sponsor changes in the story also.
The price drop for opening day should overstate the decline in demand for baseball in general. Baseball fans can substitute for lower priced games this season, or defer the opening day game experience to another year. The demand for tickets to opening day should drop relative to other games.
In New York, the Mets' have set up an auction for unsold tickets to the curtain raiser at Citi Field. The Yankees also have premium tickets left for Opening Day, at $2,625, + $59.70 S&H (Hey George, what is the 70 cents about??). These seats were likely targeted for the brass at AIG, Bear Stearns, Citi, et al. Adjusting their prices is tricky, since they're offered as season tickets at the top of the pricing structure pyramid. And who knows, the good times might return by the time next year's opening day rolls around.