I have quite a bit in my Purchase History at the moment and most of them dont show the return this item link, that is in the dropdown menu. There are 4 where return this item is visible, so it seems to be a bit inconsistant. The ones where it is visible are all from sellers I've bought from before, so it's not like it's a first time purchase. The 4 are scattered through my purchases, so not even like they were before a certain date where they may have changed the view after then. Who knows?