Three browser extensions are recommended in this short article.
I haven't checked them out yet -- personally I do most of my shopping on amazon.com and I have been very happy with CamelCamelCamel
for tracking prices there.
The first method is to compare the price between two stores immediately. The second way is to compare the price right now with the price at a different time. After all, the price you see right now may not be the best possible price for a product at any given time. Heck, if an item is expected to go on sale in a week, it makes sense to wait for the discount. The third and final way is to compare a new item’s price against a used one.
While we're on the subject, you know what would be nice? A way to filter out commercial high-volume sellers from ebay search results...