Pretty much this. It's why i sold my iphone X last week, maximizing value (luckily i have a 7+ to tie me over). The general public isn't really too aware of the fact that new iphones are coming out in a month and a half. I think people trying to sell a used X, when the market is going to be flooded (a large percentage of people upgrading are those who have an X, and will want to sell the phone to offset some of the cost for the new device) will not get the best value back. Especially since the price of the newer version is dropping; it'll crater the price of the 2017 X on the secondary market. I've already seen retailers slashing their prices on brand new X's, i could only imagine what will happen with the used market.