It's been almost 7 years since the launch of the PS4. All things considered, inclusing inflation, I think an additional $70-100 is OK. Have you seen the cost of concert tickets in the past year? They've practically tripled since the release of the PS4. Seriously, if you bought the PS4 at launch AT $399.99, then it's basically cost you less than $00.20 USD/per day. Tell me anything in that price range that's in your home and brings that much enjoyment for that many years at $.20/day. I'll wait here.
It has been nearly 7 years since the release of the PS4, and this new and improved spec sheet is beyond anything a console could do in the past. I think a $70-$100 is 100% justified. $500 for a console of this power that will last you that long in my mind is completely realistic. I am a PC gamer myself and came from both Xbox one and Ps4 to PC spending nearly $2500 for a great computer. From my eyes seeing these new specifications going it to the next Gen consoles makes me quite happy for all console gamers, they can now get a taste of pc performance at a lower price point.