What are the oldest vocal synths you can still buy straight from the producer?

[Homi-cider]

I'm trying to, in one way or another, get a legitimate copy of every vocal synth I can get my hands on(digital or otherwise, excluding endless free stuff like UTAU). What are some older, in danger of being discontinued soon, vocal synths still on the regular market? I'm aware of stuff like ZeroG and some things still available through yamaha or internet co.
They are all steadily phasing out, so I'd like to get some of those now while it's still easy.

 

[IO+]

Some VBs is still available while they are techically discontinued like miku V2 for example but most of my VBs are second-hand digital copy, except megurine luka v4/SP

if you don't mind second hand VBs is a good cheap alternative option

 

[Bookworm2]

I think you can still buy Kaito and Meiko V1 from Crypton's old website! They're about $150-ish each. You might need a Japanese address, but you could use a proxy service.
Meiko V1: クリプトン | MEIKO（音楽ソフトウェア）
Kaito V1: クリプトン | KAITO（音楽ソフトウェア）

 

[MagicalMiku]

Use a proxy shopping service and search on yahoo auctions (for used), mercari and rakuten, you can find used in very good/perfect conditions and also some brand new (especially on rakuten, since there are shops directly selling) Amazon JP sells brand new too, but usually only the most recent releases ^-^