The margins are what makes something a good deal or not to the buyer. If a company takes 300% margins on speakers, then you get more bang for your buck as it's $400 on $100 to build instead of you paying 3,000% on $100 so it's $3,100 to you. It's all the same product, it just equals more value with less margins, or as the money isn't invisibly and magically going to the speaker building company or wire building company instead of your pocket.
Lower margins = cheaper prices, and more bang for your buck on the same product
Lower margins = cheaper prices, and more bang for your buck on the same product