Where can I buy kopi luwak in London / UK?

I've been looking for cafes or restaurants that sell kopi luwak in London (also elsewhere in the UK), but I haven't been able to find any. Harrod's sells it, but their price is £500 for 250 grams, which is mad.

Does anyone know of a place that sells kopi luwak in London, or am I better off just buying it online? Cheers.