Yes and no, but mostly yes. (confused yet?) haha Cores of the early style are much less desirable, but do have their place when putting a car back to original. I happen to like them better as they're a bit more robust and longer lived. Though, they're often harder to repair/rebuild due to many of the screws breaking off upon disassembly.
The later ones are most sought after due to them having replaced the early style pumps, and they're easier to repair/rebuild. Bosch is still making them, but only in small numbers once a year or something dumb like that. It's very unfortunate that most people overcharge for them.....there are just far too many of them out there to merit such high prices. When distributors buy them from Bosch they're usually $200-$280. Unfortunately, none of us are distributors, at least to my knowledge. Everything else above that is pure profit for the seller.....or greed......it depends on how overpriced it is I suppose.
Cores are usually a $50-$100 item. It depends on the physical condition and mindset of the seller(s). They're valuable to us because our cars use them, but to what extent? Your guess is as good as mine.