Opinions are being sought. There is no need to apologize.
Dave has a good point. I would hope many people wouldn't judge the value of a tip or suggestion based upon a person's age, but it could happen even without thinking about it.
Something like this wouldn't be displayed for every post, but would be found on the member's profile. I've been giving this more thought and due to the COPPA and privacy laws, I don't know if this is something we should be doing. Anyways, with the current members page you can add your age to the bio section if you wanted to.