They arent as bad as you would think. The 320d's are more expensive as they are more desireable due to fuel efficiency. You can pic up a 57 330 or 335d for around the 10k mark but it will have been to the moon and back and prob will be an SE not Msport. For a decent 1 with low mileage your talking easy £15k which I paid for mine and that was 320d Msport with 30k on the clock. You will be doing well to tick all the boxes for under £15k Good luck.