Ebay and amazon Dropshipping

Dropshipping is when you see how much something is on amazon and then buy it and sell it on ebay at a higher rate. So if i brought an e.g. apple iphone 6 for £/$ 400 on amazon and if i advertise it on ebay at £/$ 600 , i will be making £/$ 200 profit. But i know what your saying now,  how do i buy something on amazon and sell it on ebay well it is very simple. If someone brought a iphone 6 on ebay with your ad selling one all if have to do is buy one of amazon but put the buyers information in. But when the buyer gets the iPhone 6 he will see an amazon box , to fix this , there are websites who will sell  brown boxes and you have to just put the sellers information in to that website. And in i don't know 5 days time the buyer will get his iphone 6. This is a simple method which could earn you big bucks. Please share this thx guys ;)