Lolz , this is not a reliable business in anyway and how many use products of yours will you be able to sell to make a reasonable amount of money.. I can't even consider it as a business because it will really be difficult for you to get people who might be really be interested to buy your used products with a reasonable price. People should just consider starting a business or engaging in anything that will be profitable to them or something that they can do for a long time without having any challenge, this is not one of them.