Prices on Amazon are adjusted REALLY fast. I always add a few things to my cart so I can see if the price drops, and there's always some change in at least a fe

Prices on Amazon are adjusted REALLY fast. I always add a few things to my cart so I can see if the price drops, and there's always some change in at least a few items. Also, as you mention, if some items are sent from the US, they might not be sold by Amazon, so they'll show you the cheapest option, but as it becomes available or not in different sellers, the price will differ. You can try to open a product at the same time on a logged/not logged account and see if there's a difference. But you need to do that at the same time.