Web Scraper / Parser / Crawler / Analyzer -Send info to .App

There is a website that displays their data in Flex format (flash). It's similar to eBay, in the sense that it has listing ID's. I want to be able to feed certain parameters into an application, and then have that application gather all of the listing ID's from the page and monitor them for changes. When something changes about a listing, it is recorded and sent to the application notification center for my review. I should be able to get the interval for the searches.