Thanks all for your help, it makes sense. Could it be they are waiting for the sale? As i booked this same route at the same time last year on 30th Aug and BA was in the sale and the cost of the seat was almost half the cost they are currently selling it for at D. I do hope that could be the case!

If you search a week prior to this they have I fares all the dates of that week and the three weeks prior also.