The solution for consumers are product/price comparison sites like gh.de and idealo.de (german). I don't know the US equivalents of those, but here they get the prices from many sellers and you can compare including shipping, filter by many spec criteria and even find the cheapest solution for a basket of items, split by seller and including shipping which I believe is a NP hard problem (knapsack or traveling salesman?).

sample listing for laser printers: https://geizhals.eu/?cat=prl