Mike, in the Alembic world the construction has improved over the years. If you look at a bass from the mid 80s and compare it to one from 2000 or so, the newer one will be more solid and have, I believe, a higher quality finish. Also, Series electronics since then have been better shielded against noise than the earlier ones.
I would definitely expect a bass built after the mid 90s to carry a bit higher price tag, and agree that a bass under three years old in mint condition is going to carry a higher asking price. That said, no one has to pay that if they want an 80s or 90s instrument for less. It's hard for the original owner of an Alembic to take the hit associated with that first sale. Bottom dollar for a new Series I today is about $10K with full discount. The days of the newish $4K Series bass are probably at an end.