I'd probably never have started looking at Porsche at all but when a Redeye started to cost $100K it put them in the same league for a lightly used Porshce 911 of course. I'd never think of buying one new though, that first coupe year depreciation is a killer, but once that happens and they level out they seem to hold for many years. The fact they haven't changed much is a good thing for a used buyer as well. Save $150K and have almost the same car.
I've been mulling this over a lot lately but do have to admit there's nothing like a V8 and the Hellcat Challenger certainly suited me. I'd have never gotten rid of mine to swap for a 911, but adding one to the garage would be nice. My Hellcat was a "forever" car for me, that is, unless something even more amazing from Dodge was made like a Redeye 170 for example. I'd have traded up for that.
The Porsche probably wouldn't be a "forever" car though. Just one to have fun with for a while.