That remains to be seen regarding S9 pricing. Purely speculation at this point.
The Note 8 is in no way a comparison to the X. It's an enormous phone with a stylus and a completely different user experience. A more accurate comparison will be the pricing of the Note series compared to the inevitable X Plus coming this fall, which will most likely start at $1100 or more for the base model device, creating a wide price gap between it and the Note 9.
re the S9 price - It's kind of already all but confirmed and it is going up. Guess we will know for sure in 2 weeks.
The Note 8 is a good comparison to the X price wise at least as both are the newest offerings from each company. Are you implying that a Note 8 should be priced higher than an X? I would not make that argument. I'd think the 2 should be closely matched price wise. Furthermore, the iPhone 8 should be priced close to the S9 and the 8 Plus should be priced close to the S9+ or vise-versa.
My .02