There is a proven way to make money from price differentials. It is not building a price comparison web service. It is buying low and selling high. The logic

There is a proven way to make money from price differentials. It is not building a price comparison web service. It is buying low and selling high. The logical problem with a price comparison business is that it matches price sensitive buyers with lowest cost suppliers. Logically, paying for a price comparison service is at odds with lowest cost and lowest price because it raises the cost and/or price. Good luck.