HELP ME WITH THIS MATH?

Show them the most expensive one first and tell them that it is the best there is. Then show them the other one and say that it is a lot cheaper but that you don't know much about the brand or quality of the brand. Let them make the decision, that way that can't be upset with you when they buy it. If the What-A-Sound model breaks they will likely come back to you to buy the expensive model because they think you were being honest with them and they know that you have the best quality one and they don't want to buy another cheap one. You'll get two sales instead of one!