Bifwynne,
With regards to markup, generally speaking, the markup on electronics is about 40%. Speakers and cables/accessories is about 50%. Markups do change, however, as the cost of equipment goes up. When you get into very expensive equipment, the markup is usually lower. Keep in mind that the info I'm giving you is not absolute; its just a general picture of the industry as a whole.
With regards to markup, generally speaking, the markup on electronics is about 40%. Speakers and cables/accessories is about 50%. Markups do change, however, as the cost of equipment goes up. When you get into very expensive equipment, the markup is usually lower. Keep in mind that the info I'm giving you is not absolute; its just a general picture of the industry as a whole.