RSS feed for ebay and other shopping sites

No one uses RSS, but it is really nice. For those of you who dont know, it effectively pulls content automatically. There are lots of things on my wishlist to buy and I periodically search to see what the prices are. I would love to have an application that could search eBay (or amazon) and basically monitor when new items are added, existing items change in price etc. Don't use the term RSS, just make it happen automatically.