Ok, well I don't know exactly what specific electronics you are talking about, but you are more than likely picking a hard target to hit straight off the bat by selecting ebay as your marketplace, and electronics as your product.
You only need to take a quick look at ebay to see the electronics market is completely saturated, and you would be looking at a situation of having to purchase in big numbers to even come close to securing a price that would even give you a sniff of success in that selling environment.
If I asked you to pick the hardest market to break into in online sales, you could not have picked a better one that electronics on ebay!
My advice, go back to the drawing board!