Eve-Prices one of the latest usefull websites for the EVE community.
If you want to know what the most expensive item is with in EVE or if youw ould like to check what your faction item is worth..

Check out  http://www.eve-prices.net/
There You'll find a database of Officer / Faction / Deadspace and Storyline item prices.

You also can download  XML dumps which can be found at  http://www.eve-prices.net/xml