I regularly visit LifeHacker which has some great stuff. They had an article recently on searching for discounted items at Amazon.com by putting ‘&pct-off=x’ where x is the amount off that you are looking for. Additionally you can search a range such as ‘&pct-off=50-70’ which would search 50% to 70% off. Additionally you can search items sold only by amazon, which increases your chance of seeing only Amazon Prime items by adding &emi=ATVPDKIKX0DER.
It gets a little annoying to add these to the address bar after doing a search so I’ve made it possible to just add it to your bookmarks so that after you’re done doing a search you can simply add these elements by clicking on the “Amazon Savings and Prime” bookmark. Just drag this link onto your “Bookmark Toolbar” or Right Click and select Bookmark this link.
There are several options for savings.
Please note that you must first do a search on Amazon.com for something and then click on the desired “Amazon Savings Search” bookmark.