Big Fish Audio is having a site-wide sale, with a discount depending on how much you spend. 10% off $19+, 20% off $99+, and 30% off $299+, with codes PREZ10, PREZ20, and PREZ30 respectively.
The VOCALOIDs you can buy are: Miku V4x, Miku V4 English, KAITO V3, Rin Len V4 Bundle (V4x + English), Luka V4x, MEIKO V3, DEX, DIANA, Avanna, SONIKA, Tonio, and Prima.
Be aware that you cannot register your Crypton voicebanks into your Crypton or Sonicwire account if you buy digital versions from Big Fish Audio. Therefore, it is not possible to get the preferential upgrade prices for any future voicebanks if you get digital from BFA. (I know this because I tried to register Miku V4x and KAITO when I bought them during the fall sale last year, and couldn't. They don't come with the codes necessary to do that.)
They do have physical versions for the Cryptons that you can buy, but I don't know if they have the Crypton registration codes in them. The rest of the VOCALOIDs are digital only.