Your basing your math on everything running at 100%. In that case, you'd be right that there would be no cost difference. The difference would be that you would have increased light output for the same amount of power consumption. Either way it's the same horse, whether you look at it from the head or the tail. You have a better power consumption value running at 230v vs 115v, if that's how you want to look at it. My math was based on equal wattage at the LED board level, which is really what we should be considering. If you want to look at the horse from a different perspective, go for it. Either way, it's a better value to run a 230v if you can. It's not a massive difference, but with a lot of lights over time, it's definitely worth it. In a tiny 4x4 home grow it's not going to be noticeable however. A 600sq ft grow op will save enough by running 230v to put a new roof on the building every 10 years. It's worth it at that level.