This light Im building uses 30-36VDC.
You can touch wires without it doing much of anything to you.
My house has a circuit that runs from 24VDC through a inverter and
powers a 120vac outlet in my living room.
On the fan...the resistor won't be cheap. Or efficient. Going to waste around twice what the fan is actually using.Better off getting a 12v fan and power supply.
Doug
Drew if you want to go by cost alone, go buy $40 worth of flo bulbs and ballast.
We can compare once I build this.
Apples to oranges.
This kit is not for everyone, I would say most any teenager could do it.