When I purchased cruising boats in the 10-17K range, I didn't get a survey and went with Liability only coverage. I felt the systems and other potential issues were simple enough, I could do a fairly good job assessing them myself. I ended up redoing most of the electrical
anyways. With liability only coverage, no insurance
survey was necessary. I have no regrets I went that way.
On the other hand, the professional surveyors can pick up something important you may have missed.
You should check with potential insurance carrier's ahead of time, but otherwise, it's a matter of what you are comfortable with.