How much does a holiday to Tokyo cost?

Does anyone know how much a 2-3 week holiday to Japan would cost? Including flight from the uk.
Me and a few friends really want to go there, and im starting to ave cash and research, hell im even learning Japanese.
as far as i know £1 is 214 yen.

Anyway thanks in advance.

I from my experience I bet it would run you about 3500 Euros for a sound and fun trip.