CamelCamelCamel is one of the five best price tracking tools.
Adam Rifkin stashed this in Personal Finance
CamelCamelCamel is one of our favorite ways to get discounts and track prices on Amazon products. We've mentioned it in our guide to getting the best price when shopping online and how to automate your discounts for the best price. You can install the browser extension (Firefox, Safari, Chrome) to get access to the site's features without leaving Amazon, or you can just copy and paste an Amazon link or product name at the web site. In every case, CamelCamelCamel shows you how the price of the item has gone up or down over time, how prices have changed through Amazon directly and through third-party sellers who list new and used items on Amazon. If you sign up for a free account, you can set up alerts so the site can notify you by email when the price of an item drops below a certain amount, whether you can get it used for a given price, or whether it's at an all-time low and now is a good time to buy. You can even see previous historic highs and lows, and try to map out when the best time to strike really is.
Those of you who nominated CamelCamelCamel highlighted how useful it is for not just finding discounts and looking to see how price cycles fluctuate for specific types of items (like electronics, appliances, and more), but also bemoaned the fact that NewEgg banned them from tracking items listed in their store. You also mentioned the fact that their Chrome extension has gone missing from the Chrome Web Store, which is never a good sign. Even so, many of you pointed to how helpful the service and the site is, and supported it in the nomination round. You can read more in its nomination thread here.
Online prices change a lot, it seems.