How much should I pay for Ardbeg Serendipity whiskey?
Hard to say. Serendipity is slipping from “Really, really hard to find” into collectible status, so the price (which I’ve seen at 100 pounds, but not 150) is now on the cusp of being worth whatever someone is willing to pay. So if you won’t buy it at 150, someone else might and that’s what it’s worth. Honestly, if 150 pounds is within your budget there are better buys out there. Look into Lagavulin or Port Charlotte or the other Ardbeg lines for peat beasts or something from Bowmore. Beyond that, you could just buy a basket of 3 or 4 really top-end scotches this lucky person will be apt to actually drink and enjoy.