Those numbers leave out a lot; and make a lot of assumptions.
Assumption 1) High annual mileage. It takes a lot of miles for the electric to be cheaper than gas. With the limited range of the zero, its harder to hit those high mileages.
Assumption 2) You follow all the manufacturer recommendations for maintenance. Many of them aren't really necessary.
2007 Yamaha FZ6, purchased in 2009 for $2000 with 2000 miles.
Sold in 2017 for $1600 and 22,000 miles.
5 Synthetic oil changes = $300
20,000 miles @ 40mpg @ $3/gallon = 500 gallons = $1,500
New rear tires every 5000 miles @ $200 each = $800
New front tires every 8000 miles @ $200 each = $600
New clutch cable = $100
Misc lubes = $50
Front & Rear brakes = $50
Total cost of ownership after sale: $0.19/mile
Compared to 2013 Zero S purchased in 2016 for $6500 with 1500 miles.
~8200 miles as of this morning.
New belt x2 = $200 each
rear suspension = (parts only) $300 OEM replacement, $850 for upgrade, $100 Chinese knock-off bandaid.
Electric costs = $0.15/kwh, 13kwh total battery size, 70 miles/charge = $0.027/mile ($216 to date)
New rear tires every 5000 miles @ $200 each = $400
New front tires every 8000 miles @ $200 each = $200
Cost of ownership = ~$1/mile
Cost of ownership assuming I can sell it for $5000 = $.037/mile
Update with things I forgot:
Insurance (comparable for both at ~$100/year)
Time and transport >90 miles for zero service as opposed to taking it to one of the dozen+ ICE motorcycle maintenance shops within 5 miles of me.
What I left out:
Upgrades, Side cases, top case, luggage frames, LED headlights, cameras, alarms, bodywork, replacement plastics, paint, frame sliders, fast charger, J1772 adapter, single purpose tools...