VW Sharan TDI 130bhp - kal

A friends new shape Sharan TDI auto gearbox has failed (reverse gear), VW has quoted 4k for a new box, sounds a touch steep to me, I have suggested he checks out a quality independent outfit that is a specialist in auto box's. In addition judging from various posts in the backroom a visit to a VW dealership should be avoided as VW dealers (not all), but on average = rudeness, arrogance, and high prices. Do we remember the advert "if every thing in life was as reliable as a VW" ha ha.

car has done 100k

I would be grateful if any body has some good advice on how to get this auto box repaired in the most cost efficient way.

Thankyou