Samsung new j7 is a third of the price and exactly the same camera... So we are paying basically $800 more just for the pen
Historically the J7's cost about half the flagships.
Also regarding J7 prime based in rumors about it:
1. smaller battery
2. No wireless charging
3. Smaller screen
4. Lower resolution screen
5. Processor will be a lower end one compared to Note 8 obviously
6. Smaller RAM
7. Smaller internal memory
8. No OIS
9. The weaker processor would mean no 60fps recording.
10. The front camera is worse
What else to expect?
1. No gyroscope. Historically Jseries skip the gyros and settle for accelerometers
2. No water resistance
3. No NFC - hence no Samsung or Android Pay
4. Jseries also historically has no sensors for auto brightness
5. Obviously no SPen and associated software features.
6. None to limited updates. Historically only the best selling J series gets updates, plus only for the one major update. After that jusy security updates. That J7 prime won't be getting Android P like the Note 8 will.
So no, the SPen is just one of a much longer list of things you will pay for on the Note 8.