With the latest game settings update in Call of Duty: Black Ops 3, the Rare Supply Drops are now available at 50% off rate if you use Call of Duty Points.

Rare Supply Drops now cost 100 Call of Duty Points from now through Tuesday, May 31st at 10AM PT.

Rare Supply Drops still cost 30 Cryptokeys.

Thanks @Biblicalreaper for the tip!