What do you think about my advised to him?
For someone who just wants to start trying to invest in Bitcoin, of course, $30 I don't think is wrong. I think for some people in countries that have a lower fiat value, $ 30 is quite large.
But you are right if we only expect $30 of course it will take a very long time to get a big profit for investing in Bitcoin.
Maybe if he is interested and wants to continue you should be able to encourage and help him to introduce more knowledge about Bitcoins. Even though there is a high risk, in my opinion we should be able to see good opportunities and follow existing developments such as investing in Bitcoin.
The most important thing, in my opinion, is that he can increase his previous knowledge about investing in Bitcoin, for the matter of investing capital it can be improved over time.
Indirectly he already knows Bitcoin through your explanation, even though he still knows a little about Bitcoin I only hope that in the future he will not be among those who regret it like most people who already know Bitcoin but don't immediately invest in it and it turns out that Bitcoin increases in value over time.