I think the way to understand the marketplace for the early cars is not to look at the cars, but at the buyers.
At one end you have the guys who are just able to put together the 6-10K (or whatever) to get themselves into an early car. They won't modify it much because they're doing well just to keep it up and running. These guys drive their car for fun on the streets, and sometimes to work. They have a blast for a modest investment.
At the other extreme you've got the big-dollar collectors who get an air-conditioned garage for their handful of S and RS models. These guys drive the cars on well-organized vintage runs.
In between are the guys who can maybe afford to do some modifications, and get to take the car to a track occasionally, or even get into club racing. Oddly, it's the poor guys and the rich guys who don't spend very much on their cars. The poor guys are happy just to have such a cool car. The rich guys generally sell the cars for big money, just like they paid for them. The cars are investments for them that they also get to polish and show.
We in-betweeners are the ones who get soaked, financially. We pay for the cash-foolish mods, and eventually sell our creations for pennies on the dollar. We also sometimes break the cars at the track (at least, I've
heard this can happen), and end up upgrading them in the course of making the repairs.
An early S will likely end up in a rich guy's collection, if it's all period correct and Concours-de-Elegance proper. But it can also end up in a real enthusiast's hands, and end up getting used in the way it was designed for. Sometimes (Chuck Miller's S comes to mind), it's both carefully preserved and mercilessly driven.
But usually it's one or the other: you either go the stone-chips route, or the no-stone-chips route.
Personally, it's my belief that if I can't blow past a Viper in Turn 8 at Willow Springs, then I'm just not using the car correctly. Polishing and waxing is boring, to me, and being able to perfectly re-create vintage Porsche sales brochure photos with my lovingly detailed car is just not nearly as fun as drifting through a high-speed turn in pursuit of somebody else in their car who feels exactly the same way.
To each his own. For my work, I write about guys doing exciting (and often illegal) things that I would rather write about than do. Real-life bank robbers might write me off as some kind of dilettante, I guess. I don't want to do the thing I write about; I guess this would make me kind of a 'crime collector.'
But when it comes to the car, I don't want to 'capture the essence' of a bygone era. I want to do exactly what they
did in that era -- race the piss out of my Porsche.
The early S is a car that goes both ways. The ones commanding the $40,000-$50,000 prices are the absolutely correct and lovingly preserved ones. The ones commanding $15,000-$30,000 are the ones that see redline on a more frequent basis. Somewhere there's a tipping point between the two.
I think the owners of the cheaper ones get the better experience, ultimately. Although I'm sure there are many collectors out there who are perfectly happy doing things their own way, and wouldn't trade places with a racer in a million years.
Different strokes (and bores, and compression ratios) for different folks.