All existing price comparisons websites (Google Shopping, PriceGrabber etc.) were meant to compare prices among e-commerce websites only. For instance, try "nexus 6 san francisco", Google Shopping will give you 10+ purchase links. But if you want to physically try this phone before buying it, or if you have to get a new phone today and can't wait for the shipment, Google Shopping will say that there are only three places in SF where you can get it (all BestBuy). This is obviously wrong. This is the gap our product fills. We allow you to search products available on most e-commerce websites (the easy part) as well as in most physical stores (the hard part).
I think either Django or Ruby on Rails would do. You can roll out these basic functionalities in less than 2 hours if you are reasonably familiar with these frameworks.