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)...