Badger_erich
I have a very close friend who owns a high end brick and mortar retail audio store (remember those) he is kind enough to sell me his products at his dealer cost and has been doing that for decades so I know exactly whay he pays for his gear.
Most electronics have a 40% markup, though not all. Some speakers have 50% but not all brands, some are still 40%. Cables can be a little higher depending on the name brand, usually 50% and he sells one name brand that has 60% markup but that is unusual. So, the answer to your question is 35% - 60% markup depending on the name brand. The problem is that they rarely do high volume. He may hit a home run one day and strike out the next day. Take into consideration, rent, salary’s for employees, insurance, taxes, etc and you soon realize he isn’t getting rich. There’s an old joke in high end audio that asks how do you make a million dollars in high end audio, you start with 2 million dollars. He does it because he loves it, which in my opinion, is the right reason to own a high end audio store! Take care and stay safe.
Scot