Except for immediate family, I've always stated a ridiculous price. Honestly, I found very early on that it just wasn't worth the hassle.
It is also one of the reasons I preferred to give old laptops etc away rather than sell them. I can then, with absolutely no guilt, say that they got the laptop for free but there will be no support.
Of course, it doesn't stop them trying but they get short shrift.
As much as I enjoy working in IT (and I do), I don't want to be doing it at weekends and evenings for other people.