In this case a premise was rented by the Duke of Westminster to someone in Pimlico (reasonably central London, at least by today's standards, and a fairly expensive area if i'm not mistaken) for £10 per quarter. I ran it through an inflation calculator and that's worth simply about £500 in today's money. That still only works out to about £42 per month. And apparently that was a place that was big enough to run a brothel out of!
What am I missing here?