I think this is a little known fact. I picked out a nice little netbook on Amazon that was a good deal. Stuck it in my cart and was going to wait a couple of days to purchase it. When I went to buy it the price had gone up 35 bucks. Deleted it from my cart. Didn't go on Amazon for a couple of days and then went back. Price had gone down. I got it.
I never save things to a “list”. I will look at an item and not buy it immediately.
I don’t clear cookies as a previous poster said, bit I look, look at similar lower priced/lesser quality and leave.
Come back in a few days, do the same routine. Then leave it for a week or two. Then come back and look at it and it may be the same price, but usually lower by a few bucks, or 20% in many cases.
The key it is to use their “trackers/cookies” against them.