How to compare two price by date and item..
For example Compare price lcd and give me color bar to tell me rate up or down>>>Not For all items and all prices
This is not trivial, and has a number of prerequisites - The things you are trying to compare must have a unique matching key - a model number/product code or similar.
Also what if an item is new or has dropped off your listings? I assume you want those also highlighted?
As it stands if you have 3 different products all called LCD it won't work.
As JDraw said we could do to see a larger set of your data and what outcome you expect.