Check engine light - Told to clean carbon from intake valves - How to fix this with minimal cost?

Hi,

Recently got a check engine light on my 2006 VW PASSAT, I took it to the VW dealer for checkup. They came back saying, “Need to remove intake manifold and clean carbon from intake valves”. For this repair, the price they quoted me is $700. If i take it to local mechanic, will the price on the repair will come down. If so, what is the minimum price i have to pay to fix this issue.

I wanted to know if i can drive car with this problem not fixing it, will it lead any other problems.

Please do provide your inputs on how to fix this problem with minimal cost.

Thanks
Sunil.