One thing you should note. The biggest powersellers make between $2.00 and $10,00 on average per item sold on ebay. This includes the sellers that sell electronics This is where the majority of new sellers think they can become millionares just by finding a specific supplier. One titanium powerseller I know of sells 25,000 items per month. All of his items are dropshipped by dbldistributing and 2 other suppliers . He never touches the product. But he makes about $2-$4 dollars per item. He just quit ebay completely because the new changes has completely killed his profit margins.
Ebays recent changes will add about $11.00 to every transaction he closes. Meaning they will bankrupt his company in only a few months if he continues to sell with them.
So in order to figure a good margin you must consider what will a fee increase do to your bottom line. What works today can be lost tomorrow. There is so much to consider when deciding profit.
Overhead( Warehouse bills.power,gas,trash,internet, supplies, boxes,shipping costs, fuel for company driving)
Final Value Fees
Extras ( gallery plus, and other options you add to each listing)
CC processing Fees
I would recommend if you are not knowlegable in this area to visit Link hidden: Login to view where you can try the courses and learn from the top powersellers.