After looking at a few websites etc I'm finding better and better deals on the petrol but not many at all on the diseasals. Considering it will only be doing around 10k a year I would have thought, I don't think the tax and fuel savings of the diesel would cover the extra on the initial price.
Finding brand new factory T-Jets for £10k now, whereas there doesn't seem to be anything below £12.5k on the diesels!