Refurbished / Renewed electronics to Amazon

I want to start selling refurbished/renewed electronics (laptops, desktops, firewall, etc..). I want the brain of this group of pros and cons of such a business idea. In addition, any suggestions on how to source these goods to be refurbished are welcome. I have the idea and the know-how of how to put things together to get them conditioned to sell but I have no idea where to buy these laptops, desktops at a price that is worth my time and my money. In other words, where do I source them in order to make a profit.
Thanks everyone.