You will be paying NRT pricing if you buy there.

I find for duty free most US airport pricing is better than NRT. Buy it in SEA duty free or your last US airport when you are Canada bound. The only one that I have bought at NRT transit were Hibiki or Yamazaki.

I usually buy my Scotch at HK independent Merchants and put it in checked baggage inside a padded leak-proof wine carrier. Back streets of Sheung Wan is where I go. You can find stuff there that are not commonly in duty-free shops.