Is a home inspection of lead worth the money or will it basically tell me what I already know?
Beyond simply identifying whether you have lead, there are two main reasons to consider getting a more thorough XRF lead inspection:


If you're trying to fully de-lead your home, this is a thorough test to determine if the deleading project has been successful.
If your goal is to make your home safer without going as far as a full deleading project, you can use XFR to prioritize remediation work. For example, you may find that some areas do not contain lead and can be safely ignored.


For safety impact, the most important rules are:


Any repair work should be done with proper personal and work area protection. Work done without proper precautions is a major risk for dangerous levels of lead exposure.
Peeling or chipping lead paint should be safely removed and replaced or covered (e.g. with an encapsulating primer designed to secure lead paint). 
Lead paint in areas subject to frequent motion (e.g. window partition beads, door jambs) or in child-accessible areas (e.g. base and window molding) are higher priority for remediation.
Keep your home clean (vacuum more often with a HEPA filter equipped cleaner).
Supervise your children and/or remove lead paint in their primary play areas.
Watch out for any new paint chipping and clean or remediate as needed.


Of course, it is safest to fully de-lead your home. You should come to your own conclusion about how much risk you and your family are willing to accept around this.