I would think a 54 plate 320 CDI for £10k will either have been round the world or have no service history or been a total loss, but Your'e budget would get a reasonable 02
with a few miles on so look out for Valeo problems(do a search on here) and also check for rust, otherwise save up a bit more and go for the latest one you can afford, I reckon the E211 is a lovely car and if looked after should last a long time.
I looked at the E320 CDI a few months ago, I did see a nice 54 estate for £10.5k mind you it had done 104000 miles which put me off a bit. There are lots of cars out there around the £10k. In the end I brought a C320 CDI estate for £11K which has the V6 diesel 7 speed auto which seems much smoother than anything else I had driven.
I would avoid a e320 cdi at all costs, black death and numerous electrical faults in my experience
I have an 04 E320 cdi and FULLY recommend it. Now 102000 miles on the clock and drives/feels like new.
By the way what is this 'Black Death'??