Pass due to not having enough gems and i try to stow away from main boxes. I'm still trying to get cards from the first box when this game came out and onwards so i never save my gems which i really should.
The half off only apply to cash, not gems. I'm not an avid spender like everyone else who drops 300 or more a month trying get 3x UR. I'm not that damn desperate
There have been two sales where packs from old boxes can be bought for 25 gems each instead of 50. I wouldn't be surprised if they do it again for the 4th anniversary.
25 gems per pack for 1 whole month during Zexal release celebration, everything 50% from 1st main box to 15th mini box. Those who say "I don't know anything about this" are surely noobs.