ISO Whisky - Ardbeg Uigeadail
Cheapest place in town in Heights Chateau, $71.
While they have a huge selection, Park Ave Liquor is consistently the highest priced place in the city for pretty much anything - for example, this particular one goes for $85 there. Pretty much guarantee any spirit you're looking for available elsewhere will be cheaper than it is at PAL.
123 Atlantic Ave, Brooklyn, NY 11201