There seem to be lots of people taking classes that will pay you to do their homework for them...
You could offer classes. You could consult. You could build a bigger better gadget that happens to include an Arduino. these are fancy ways of "buy low, sell high" - "nominal fee for the class, plus you'll need your own Arduino, and I can sell you one of these $5 Nano clones PLUS a USB cable for $15; much cheaper than <real Arduino.>"
You could dress in a bikini and do video tutorials about Arduino, and collect advertising dollars from Youtube.
You'll note that some of these require a good deal of expertise, and/or ... other attributes.