All ingredients are standard grocery-store stock at any Charlotte chain, with demerara sugar and Irish whiskey both readily available at Harris Teeter, Food Lion, Publix, Walmart, ALDI, or Kroger without a special trip. The cost per serving runs about $3 to $4 depending on whiskey quality, driven entirely by the spirit; everything else is negligible. The five-minute timing is honest if you already have hot coffee brewing, though realistically you are looking at eight to ten minutes if you're starting fresh and whipping cream by hand. This is a single-serving cocktail with no leftovers and no reheat value, so it works only for a weeknight if you are the only drinker, but it is simple enough and impressive enough to justify the modest expense for a special occasion or an after-dinner treat.