As an update, Kavalan is definitely something you want to pick up at TPE duty free if you're a whisky fan.

Big premiums (30% to 50%) in price if you try to buy it abroad, even if you can find it.

If you're looking for one of the finer bottles, look into multiple stores - they don't all stock the same. When I was there last week, most stores had the regular single-malt, bourbon-cask, and sherry-cask.

If you wanted the Sherry Fino (about $200usd) or Manzanilla... look into more stores. I went through 5x different ones before finding the Sherry Fino.