Are you sitting down?
http://www.skandix.de/en/spare-parts...-unit/1044623/
I think this is the correct one, but the Skandix site lets you put in your VIN number and select the exact model and year, so worth double checking.
You could also ask your local main dealer for a quote.
... The above is assuming that you are talking about the electric tank sender pump, not the two stage common rail pump on the end of the camshaft.