Actually, a good result on the PSAT sets you up for national merit scholar and merit-based financial aid in college. It may be intended to be a practice test, but the possibility if the merit scholar thing means I wouldn't hesitate to prep for it. (and I'm super anti-testing)
Yes but that is ONLY when you take it in the fall of your junior year. This is a PRACTICE test for a Practice test (PSAT). Seems kind of silly but as you point out there are a lot of stakes in this particular test. And I know of many schools that pay for all of their kids to take the PSAT as both 9th & 10th graders even though it doesn't count until junior year. Thus I want him to go into this one without a lot of prep but not zero. In general I'm not into overly testing.. but the first step to see how much prep he needs for next fall will be this test.