If you place an Amazon item in your wish list and leave it there a while, if the price drops below what it was when placed in the wish list then they will indicate how much of a savings you can get. For example:

This practice is rather good and I wish it extended to all items listed rather than just wish lists.

But I think the "list price" practice, as I said typical to USA marketing, is total bull scatterings. However I don't believe in legislating against it. If someone is dumb enough to fall for it, and many are, then so be it. You cannot legislate stupidity. It is pretty easy to compare prices these days with a search engine and the internet.