I always thought that it'd be a nice feature to have some basic pricing info on the individual park pages. Obviously, you can't list everything, but it'd be cool to have the main things... park admission, child admission, parking, 20oz drink, bottle of water, souvenir mug, burger, fresh cut fries, etc. The basics that pretty much every park has. Pick 10 or 12 items, and list the prices of them. Maybe even make them crossreferenceable (that's a word. shut up.) so you could bring up, say, Dorney, Kings Island, and Busch and compare them.
Not sure how important of a purpose it'd serve, but with so many people scrutinizing pricing, it'd probably be a pretty popular feature. I'd like it just to see how things trend in different regions.