Economic Influence is based on decisions on the price of the product and how good the product is.
People would buy an expensive product either because the product has limited amount coming out and also they must have a discount on the for example buy one get one free promotion on the product. They could also get more credit if they buy a more expensive product and be able to get enough credit to get products free as some grocery stores promote. But very limited of people would buy the product because the product is great. Also when people get to the register cashiers ask if they want anything extra right in front of them which probably has a sale on it and most people would take cause it would be right next to them.