My Dad and I used to comb my uncle's farm looking for points after he would spring plow. I usually found some flint chips, but my Dad had a keen eye. In one week he found a Hopewell celt and an Adena celt in the same week.
Man, those things are so catchy, but treacherous. A few moths ago, I almost bought a small collection of arrowheads on a garage sale (due to temporary loss of sanity), but luckily I quickly recovered my common sense before dishing out all that money. I told myself that although the guy seemed very honest and knowleadgeable, what if all that is smoke and mirrors, and the collection is a fake? You either learn a great deal, or hire an expert.
So, I'll just stick to bonsai.
As far as the point of this thread is concerned, I find it amazing, how many people take the free advice of experienced people for granted, as if they are entitled to it. When I see a novice who started the hobby 6 months ago, argue with somebody who has been the student of this art for many decades, I realize how undeserving these privileged brats are. I still believe that a true lover of the art should make a lot of effort to spread the knowledge, but I also see that some people are not worthy of it. This must be the reason, why the masters of the old (before the Internet), were so careful to select their apprentices. It takes great effort to teach somebody the right way, and the student must be ready for it.
With bonsai, I would separate the information in two categories: popular bonsai information, and hands-on, in-depth bonsai information. The Internet is great to disperse popular art and science, to whet the appetite. It is also great for advertising someone's epxertise, without giving away too much. Then it's the student's turn to make the effort and seek out the knowledge. And that is not going to be free. It all depends on how serious you are about learning. Some people are more than happy with just scratching the surface. This is a hobby, after all.