It will vary depending on many factors, so what happens to others isn't likely to be the optimum path for you. You'll have to experiment to learn how well you do and adjust your bids and other control factors from there.
As a guideline, I generally start with search only and run for several thousand clicks and at least a few dozen sales to figure out that my search network bids are close to their optimum (optimizing further on an ongoing basis. But with some search data in hand, I often then venture into content with my bids starting at 1/3rd my search bids. Thise content bids then are also adjusted as I monitor things. Sometimes I bump them up considerably from my 1/3rd start spot, sometimes down - just depends on how well I'm doing.
It's rare, but has happened, where my content bids (after tuning) end up higher than my search bids. So point is, try it, track it, adjust to suit your needs.
When you set up a campaign you can select Google search, Google Network, Content, and some other content one - can't remember the name. ie there are four check boxes. Has anyone tried not selected the second check box (which Google automatically checks for you) ie the Google Network box.