I think its worth it cost difference between a 21 and 22 isn't much more. A 22 Redeye is only $1300 more base MSRP than a 21. The 2k incentive is pretty crap anyways most people rather take the 0% financing for 72 months which is great free financing. There a 3 vendors on this form as well that can factory order you a car 5% below invoice cost which is roughly about an 8% discount off sticker. Im about to pull he trigger on ordering a 22 redeye through one of them.
Redeye vs hellcat is a very big difference IMO worth the 8.5k and it's not just power figures. Its a stronger motor, bigger supercharger, SRT chiller, I think stronger tranny (I could be wrong), different fueling system, and some other goodies I can't remember off top of my head.
If you can do the jump it's worth it but if you are content with what you have the saying goes "don't fix something that isn't broken" a normal hellcat is bonkers as it is and lets be honest 99% of people dont know what a redeye is most people just go "OOOOO LOOK HELLCAT"

.