So i have all of the Ultimate universe in both comic form and trade paper back form as well. However i want to slowly replace the trade paper backs with the official comic issues. It will be very costly and was hoping to sell the trade paper backs for to help fund my spending. So my questions are, does anyone know any good sites where i might be able to purchase cheap copies of the comics and any place where i might be able to sell my trade paper backs as well. I would use ebay but you are never guaranteed a sell.