Here's some info and opinions:

With the same memory S8+ and Note8 has a price difference of Rp 500.000 to 700.000 (around 35-50 USD). The unlocked S9+ 128GB   stands at Rp 12.420.000 (870 USD), with the same trend i would expect the unlocked Note9 (128GB) without any gimmicks would release (in the official store) at around Rp 13.000.000 (900 USD).

Unlike iPhones, Android flagships that comes officially (by officially i mean they sell it in Indonesia because they pass TKDN regulation) in Indonesia tends to be cheaper than some of other countries. For instances, Oppo Find X is released here (in Indonesia) at Rp 13.500.000 (936 USD) while elsewhere release price is up to 999 USD. And please mind that prices that i mention above is from Samsung's own official stores. Other stores might sell with lower prices, with price differences up to around Rp 1.500.000 (104 USD) with Samsung Indonesia (SEIN) warranty or far below that with only distributors warranty.

Personally, other from CPU, RAM and ROM updates, Note9 is only a tiny bits of software exclusive update that doesn't really worth a step up from Note8. For a premium phone with a pen, Note8 is still a really capable phone with lots of software support.

One more Note that is still up there above some midranger is Note FE (Fan Edition). Bearing a water and dust resistance that might not featured in middle spec phone, along with even an older camera that is still better than most midrange phones and CPU that if not on par, is above what midrange class offers now, it's the best bang for the buck Note series phone if you can find it cheap. Sadly some software that is compatible with same spec S7 strangely not compatible with it (like ARCore for instance).

I wonder why there is no competition for a phone with a pen like the Note series. Clearly it is a good device and the pen is a good addition for a large screen phone if not useful. The other phone with a pen i know is LG Stylo series but the the spec is far below what Note series offer. I do hope there is a real midrange phone with a pen included, and hearing things about unification between Note series and S series, i can only hope they keep the pen.