How imperative is a brake vacuum pump replacement? What is this? on 2006 Volkswagen Jetta

I recently had my car inspected and was told (with great urgency) that this needs to be replaced. I was also given an estimate of $738. My car currently has no symptoms of an issue.

Asked by for the 2006 Volkswagen Jetta
1 answer
That is what helps you apply the brakes. If it goes then you will start to get a very stiff brake pedal make for difficult braking. Anything on a VW is difficult so I would say might be serious.