I got this tip from Jimmy Henderson of the 3DS/Wii U facebook group.
PSA: Fire Emblem Fates releases today. If you want to get the digital version of Conquest or Birthright after already buying one version of Fire Emblem Fates, buy the other one from the menu in the game, NOT FROM THE ESHOP.
The initial game is 12,467 blocks. If you get the other two as digital downloads, they are 797 more blocks each.
According to fans, it is also cheaper to buy there.