Repairing scratched, curb rash black wheels on Porsche and Land rover

Repairing scratched, curb rash black wheels on Porsche and Land rover for under $10. Getting a touch up from a local shop costs $125 each and my time. Using a similar process to this. Or re powder coating the wheel is $150 each and removing the tire and wheel from the tire and my time and at least 3 days without the vehicle. Not worth it.