I've seen many posts mentioning reporting an item's lower price from another e-tail website to Amazon. I looked on their help page and couldn't find anything.

Does anyone know how to do this? Thanks.

You do it on the item's page. Down near the bottom of the item's listing, there is a line that says "Would you like to update product info, give feedback on images, or tell us about a lower price?" Click on that and you can fill out the form with the appropriate info.

^ Thanks much.