I have to admit I wouldn't even bother getting one refurbished. Id but new. I know it's a lot of money but it's peice if mind and alot of miles.
We're talking serious money, even if it is still available. The same pump went on the BMW, Miggy, some Passats, all sorts. The code ending 994 is the one you need, otherwise you'll get odd results. Guessing cheapest might be from Vauxhall but got a feeling all new units probably got bought years ago. Showing as Out of Stock for £2,500 on Rimmers!
https://rimmerbros.com/Item--i-STC2268