What about the guy I mentioned, Should I reach out on the basis of " Biblically speaking" or mind my own business because it's his life and right to believe and practice as he sees fit.
It is always better to discuss things openly. Weird things grow in the cramped dark spaces which we don't dare to visit in our conversations. Open the windows, let in fresh air and light. Figuratively speaking.
If I may make a few suggestions, based on my own experience from both sides of this conversation (I was a fervent Christian in my adolescence, and I also have experience with occult teachings and groups):
1. Please examine your own motivation for wanting to warn this person. What is at stake for you? Is there something you want to "make up for", and your friend's actions somehow remind you of this? Often, the things we find disturbing in the outside world mirror things we don't like in ourselves. By gaining clarity about your own "dog in this fight", you will also better understand your compassion for your friend. Jesus taught this in the parable about the speck of dust in the friends eye, in "cast the first stone", and some other teachings.
2. When you are having the conversation, listen to your friend, too. Let him describe what he does and why. Often, people who use magic to address issues in their lives, are in need of a good friend to talk to and bounce ideas off of. You mentioned his financial situation, so his money magic points to a real need in his life. As a Christian, while you would pray for God to help you, you also realize that you yourself should become active to find a better job or get a loan or ask friends or family for help - show God you really mean it. The same goes for magic: Your friend's intention to get money, expressed in a magical act rather than prayer, will have a much greater chance of bearing fruit if he follows up with some actions in the "real world", and that is where you can really help him, by supporting his efforts, doing some brain-storming, planning ahead, making a budget, whatever.
I hope you and your friend have a good conversation, which will give both of you food for thought.