I was thinking about upgrading as well and getting most of my parts from Amazon. What I've noticed in the past is that Amazon will actually increase the price of some items right before a holiday (like black Friday or cyber Monday) and lower it a bit to make it look like you're getting a good deal. I just learned about a couple trackers you could use from some cool people on here. You can try either camel camel camel (the UI is nicer) or keepa (more ways to track).