Will Apple call it the iPhone X"S", iPhone X 2, iPhone 9, or maybe iPhone XI (11) is anyones guess as this point, but what numerous sources, leaked photos and videos have pretty much confirmed 3 new models each with different screen sizes coming late 2018. We at ICY Shield Glass have already been receiving samples so we can ensure when the new 2018 iPhone models drop, we'll have them in stock.
For the new screen sizes we'll be seeing the 2018 iPhone's come in the same 5.8" on the current iPhone X as well as a new 6.1" and a 6.5". I can see Apple using the "Plus" branding on the 6.5 inch version and should be the most popular one (I can't wait to get my hands on it).
The current iPhone X uses a gorgeous OLED display and is rumored that Apple will use OLED displays on the 5.8 inch and 6.5 inch. A cheaper LCD display would be used on the 6.1 inch which suggests that this version will be targeted as a "entry level" or "budget" iPhone. We can expect the OLED 5.8 and 6.5 to be the premium flagships with the 6.5 Plus being the most expensive out of the 3.
How much Apple will price these models is up in the air, and I wouldn't be surprised if Apple increased the starting price for the Plus version to $1099.99. We'll just have to wait and see until Apple unveils the new iPhone models at their press conference event that should take place this year September.