It is a very interesting fact that when you increase sales, you plan to reduce your costs. I'd like to know how you will manage to do this. In fact, prices for goods in your store should decline with a reduction in costs.
The prices for new phones will be higher, like if the sales for the iPhone 7 increase and will get replaced by iPhone 6 sales for instance, so the average purchasing value we see atm is quite stable and even increasing for some categories like Apple iPhones.