I found that Basic -- especially using the Mentzer solo adventure -- is a great teaching tool AND it is simple and streamlined enough to have an 8 year old "get it." I think the PF Beginner Box -- which I adore and think is a highly necessary product -- is a little tough for my son at 8, but is probably good for 10 year olds. Granted, my son isn't a great reader, so my perspective might be skewed.
And, to be honest, I taught him to play not only with the same set I learned with, but the same physical copy (a few years ago, my mother dropped off a box of stuff from the basement that included old Dragon Mags and that book).