Startup Idea: Price Comparison and Historical Trend Analysis Tool

Startup idea to develop a software solution that not only consolidates product prices from multiple online retailers into one spot, but also displays price trends over time and calculates the net cost including shipping. Such a tool would simplify the process of price comparison and purchase timing decision-making based on past price trends.

I'm a mechanical engineer and work for a company that had hundreds of people who work to create tools, so I don't need anything for work. But my family and I often spend a lot of time researching things we intend to purchase on the internet. We check amazon, walmart, home depot, anywhere we might find the things we're looking for in order to get the best price. Rather than blindly search through google results, it would be helpful if results were consolidated into one spot. And not just a list of what the current prices are, but also how the prices trend over time, what's the cheapest net cost including shipping. I, for example, am planning to finish my basement. I've been tracking 2x4 prices at home improvement stores for the last year and have discovered the cheapest time to buy them is in Jan-Feb. IT took me a long time to do that. If there was already a history I could see (with respect to price), I'd know where the bottom is, or eve if there is one. See my idea above. At the moment, it's just brute force and time.