Neighbor Makes Herbal Incense

Neighbor Makes Herbal Incense

I spend most of my time after school at home alone so I have plenty of time to sit around on my back porch and do nothing. In my time on the back porch I noticed that our neighbor to the right had daily ritual that was really strange. Basically in the morning he would set our a bunch of trays on his back porch. Periodically he would go out and check on it and adjust the setting on a fan that was blowing on the trays.
I watched him tending the trays for a week straight before venturing over to the fence and asking him what the heck was going on. He told me that he made herbal incense and sold it to people around town. I asked him about it and he invited me over and showed me the whole process and  how to make spice. Basically he makes the stuff for about a cost of $100 a batch and makes a profit of over a thousand dollars. That is something I would like to get into. I don’t know a lot about herbal incense spice but my neighbor says everything he does is legal and I could make a lot of cash helping him out. Before seeing him I had never even heard of spice let alone knew where to buy spice. Is it really legal and do you think I should risk working with him?