I always put things on my wish list so not to buy them inadvertently and check from time to time,they will always tell when the price goes down but not always an increase.
Things will change in price,sometimes hourly. A great tool to use when shopping Amazon is
camel camel camel just plug in the url of the product on amazon and it will show tracking of the low and high price and you can enter the price you want to pay based on that info and they will E mail you when it gets to or below the price you set.
I always check there if the price seem to be high to me.
Bought a lot of things this way,at very good prices.