First of all, you must know about the product/category you are going to sell. Many sellers feel that selling the hottest items will earn them the largest profits. However, they ignore the fact that the most popular items will drive the profits down due to the competitiveness associated with them. Many sellers will be out there to sell that same item, which will not be a good thing for you.
Therefore, it is important that you look for specialized items which cannot be easily found in the market. Moreover, make sure that you have enough knowledge about the product that you are selling so that you can buy it on the cheap and resell for extra profit.
The other aspect ignored by most is the selling cost of your items. So much emphasis is given to the profits that one tends to ignore the ‘profit margin’ aspect of business. It is important that you get products at a relatively discounted price at the first place or seek ways to reduce your overall business costs. Whenever you decide to buy an item for resale purposes, make sure that it is high in demand and you have not paid more than what it is worth. Therefore much will depend on how you manage your overall costs related to the items you are selling. These will also include paying close attention to eBay’s fee structure as even a cent of difference in the listing price may cause your profits to go down.
In other considerations, make sure that you avoid selling high risk items. The goal here is to buy items on the cheap and then resell them, and doing this exercise again and again. Many sellers try out their luck by selling items such as Gucci, Rolex etc which are not sold in large numbers. Moreover, some set the base price too high or charge too much in shipping cost, without knowing the approximate market value, in the hope that buyers will be mislead into buying. That allows other sellers, who have done proper research to build their own client base.