A4 Avant general buying advice

[JNMann]

I've wanted an A4 since I bought my old Passet but couldn't quite get to the slightly higher price point at that time!

I currently drive a Volvo V70 D5 which I love but have to do a few bits and bobs to keep her going.  In the meantime I started looking at A4's again and wondered if this may still be a good direction to go in?  My Passets of similar age were always great solid cars and generally no issues.  Would an A4 be somewhat similar?

I'm looking at diesel cars around 2004-2007.  Found a lovely 2004 with very low mileage on but price is high.  I don't mind higher mileage as long as it has FSH and is in excellent condition.

Would appreciate any advice, comparisons to my V70 on diesel costs etc.