Right, I've just searched ba.com for flights leaving NRT on the 21st December and leaving LHR on the 29th December (avoiding Boxing Day, which is the 28th, and thus could be more expensive), and it came to "From ¥32500", which is far more realistic. Bear in mind BA quote you per leg, so that's ¥32500 each way, but it's far more in line with what I'd be expecting to pay.
I've flown LHR <-> NRT with both Virgin and BA, and they're equally as good as each other. It's common to think of BA as the expensive option, but they can be just as affordable as Virgin
