I have a doubt about the sentence below, which I made up myself. I would fill "will have been purchased" in the gap. "will be purchased" would be wrong, wouldn't it? However, if the verb was "sell", either "will have been sold" or "will be sold" would work, right? "The new phone is in stores now... You'd better get hold of it immediately. If you don’t hurry, all the phones (purchase) _____ by the time you get to your store!"