I still think apple can sell the new 5.8 oled at 800 because if you look right now apple still sells the SE,6s&6s Plus, 7&7 Plus, 8&8 Plus and iPhone X. So right now they have a lot of devices from the entry level to the high end. If they decide to kill some of these models they will need to fill those price points.
Since those older models are competing against midrange android devices at carrier stores. To keep the number of phones up, while making a profit on each device. It is possible apple could charge less, plus its almost a year since the X was announced so by now they are able to manufacture it for less and so they can pass the savings to the consumer.
The cellphone market is saturated, with 2 year contracts gone and carrier financing the new norm, people are not upgrading as fast and some have turned to the used market.