On a cost per click (CPC) basis, LinkedIn ads tend to be significantly more expensive than  Google Ads, though exactly how much more expensive can vary greatly depending on the ads you test. What is more important, however, is your cost to acquire a marketing-qualified lead and are your LinkedIn leads more qualified and easier to close with a higher lifetime value than those of Google. 

One of the reasons that LinkedIn bidding is so much higher is that the average B2B sale is far higher in value than the average B2C or D2C sale, so advertisers are willing to invest more in securing those clicks.