Advice is quite good but it doesn't take into account the specific nuances of a particular situation of the person. For example, if he only has a thousand dollars, then buying 20 coins at once is not a good idea, since it is not the best idea to divide such a small amount of money. But if he has 20-40 thousand dollars, then this option is quite acceptable. If he has more than 50 thousand dollars, I would diversify the portfolio even more, including also risky options to it.