Unfortunately, I think the only place you can get that particular whiskey is in Taiwan/Taipei, at Kavalan's retail stores. Who knows, maybe they'll start exporting it here if there's enough demand. Ask your local wine store merchant to see if they can order it for you. Yea, Total Wine in Tustin does carry three other Kavalan whiskeys, but they are not as highly rated.
Yea, Costco does carry a pretty decent selection of popular whiskeys. I saw they had their Kirkland 21 yr blended scotch for $70. Anybody tried it?
But, if you want to impress regular people, can't go wrong with a bottle of JW Blue Label and a Macallan in your liquor cabinet.
99 Ranch has the JW Blue on sale for $129 this week (today might be the last day). Cheapest I can remember is maybe at Costco for $120 when they go on sale.