Be aware that older BMW diesels suffer from disastrous engine problems check before purchase that the model you choose is not affected.

Perhaps consider the 525d facelift from late 2007 onwards? Better performance, economy and cheaper road tax too.

That will get you a lower mileage car with most of the performance (easily sorted after a remap).

As a bonus these come without the swirl flaps which are a tasty treat on the other engines in the range.