Don’t just pay whatever Amazon wants to to pay, you will be surprised by how much prices can vary on Amazon.

CamelCamelCamel is a website that tracks the prices of all the items that Amazon sells and graphs them overtime.
It also allows you to set up an alert which notifies you when the price has dropped below a threshold that you can set.

An example:-

Nikon Coolpix L340 Camera – Black (20 MP, 28x Optical Zoom) 3-Inch LCD

Just under £135 at the time i wrote this.

The tracking page on CamelCamelCamel

You will notice that the Camera has been sold for under £175 and for more than £250, so you could have wasted £75 by shopping at the wrong time.