The January 2010 edition of Corvette Magazine has a feature, changes, upgrades, etc. recap on each year of the C5, from 1997 to 2004. When the 2012 models are available for delivery, it would be expected that the C5 prices would decrease, especially as the dealers will want to sell out the 2011 models.
The Corvette Forum has a C5 For Sale section:
C5 Corvettes, 1997 - 2004 - Corvette Forum
Very pleased with my 2002 Z06, bought new, except the one cup holder is tiny. Personal preference of the driver, the short throw shifters such as Hurst, have a different feel than when used on a conventional 4 speed. Replaced my Hurst back to the factory shifter. Performance, etc vs cost, C5 is an excellent value. If you do buy, consider an after market exhaust such as Borla, terrific sound.