For all those commenting that you can get a newer/better car for the same 3k - yes, but obviously Darren made a choice of going to a reputable dealer, which in this case worked well for him as the dealer fixed the faults and agrees to full refund - now we all know that not all dealers are like that, and this is an understatement... so I think it's down to personal preference - pay a bit more and buy with warranty you can bank on, or rely on your own knowledge and look for a good cheap car yourself...
As for the state, yes it does seem to be facelift even though it is a V99, and this in turn also explains the price difference - it is common for car to drop in value when a new shape is launched even if it is mostly cosmetic.
So in short, considering that the dealer seems reliable, and that Darren is apparently happy to pay more and buy from a reliable source, I personally see no problem for him to get another car from the same dealer, though I do suggest that he does not feel pushed into it and only buys the car if he is happy with the spec/mileage etc.