Don't know about $25k, but a really nice 280SE

[ptashek]

To properly restore a car, the going time frame is something around 2,000 hours

I think this really depends on the original specimen, and there's no "going time frame" as such. Or maybe, if you're doing nothing but a single make and model, you can trust your gut then.
But realistically, you don't know for sure what lurks underneath all that "nice original patina", until you're well invested in the project. Take my 450, a very decent specimen by UK/Irish standards - I've known the full extent of body work it would require only after it was dismantled and sandblasted almost bare. We're talking just under 200 man-hours at that point already.

So yeah, I guess I need to concede to the "original is better" view, but t's not so much better as cheaper. From an investment collector's perspective, it's definitely the better way. That's where the business is. Go to shows, win some ribbons, make a name for the car, sell on with a profit. Rinse. Repeat. From a practical long-term ownership perspective, which is what I'm aiming for, all of that is quite irrelevant.