Heh, I had a very dorky spreadsheet I made when researching my next commuter last summer. It broke down my monthly costs down to spark plugs, vale shims, sprocket wear etc. The Zero was still more expensive but, there was a solid argument for it - kind of depends on how I value my time as someone who does all their own maintenance.
My commute is about half twisties and half highway over 80 miles per day. I prefer fully faired bikes for commuting because I think they're better in rain/fog and they tend to be narrower for lane splitting. I was also leaning toward a sport bike for the twistie portion of my ride. I wanted it to be cheap, have long maintenance intervals and be very fuel efficient and have a big gas tank. I was trying to be open to bikes I wouldn't have normally considered.
The Zero covered many of my requirements but, there was a possibility that I'd end up car pooling again and I didn't want that larger payment if the bike ended up sitting in the garage most of the time. On a gas-powered bike more than half of my monthly costs go away if I'm not riding it and the Zero's would remain constant. So, I went cheap. The RC isn't the cheapest in its class but, it's still pretty cheap ...and very pretty. I really wish Zero had a sport bike version of their bikes.
I've ridden various versions of the Zero MX bikes (like
this one) but, I'm a few years behind. It was pretty fun! I was sad when they switched from the left rear hand brake to the more conventional pedal: The hand brake took some getting used to but, easily dragging the read brake in both left and right corners was awesome!
I've been on the Ducati since the KTM broke down on March 18th so the KTM feels little, weak, the suspension sucks, the front brake feels kind of wooden and the clutch pull seems too easy ...so, about the way it should be. 
