you will not be able to find cheaper then ebay unless you have 100k to spend on a large minumum order from a wholesaler. and you also need a legal business to buy from real wholesale.
with the high copies you wont be able to sell those on ebay under iphone name because people will notice it is not a real iphone and your account can be suspended and a lawsuit can be pressed if the trademark company want to sue you. ipods and iphones are not the best thing to start to sell.