On most of these single vessel systems available, why is it so much more expensive to go the 240v route rather then the 120v? I mean, the PID controller itself is the same cost, granted you would need to use a little larger SSR and heatsink, but that cost should be negligible, you would probably have to use a contactor or relay, and again not a huge cost. I would think the difference in cost should be no more then about $50-$75, not the $400 premium that I am seeing online