I dunno, there are plenty of cheap spirits that taste perfectly fine. The less expensive (but not cheap swill) gins I see in my local markets (Beefeater, Tanqueray, Gordon's), and the whiskeys or scotches (like Teachers, Jack, etc) are all under the equivalent of 20 pounds, and they're easy enough to drink.
Or maybe the UK just has expensive spirits? I know in Australia you can't get a bottle of literally any spirits for much less than $50-60.