Why but one ? you can pick a low mileage used Harley all day long for 10 grand and have 20 grand left over for gas. It  doesn't make much sense to go electric. At $3.50 a gallon 20 grand will buy you 5714 gallons of gas ,at 35mpg you'd be able to ride it nearly 200,000 miles.(without watching your electric meter spinning off the wall, when  converting AC to DC there's a 29.3% loss  )  and it allows you to ride anywhere, anytime and any distance.