My car gets 8km/L real-world, so 800km is about 100L of gasoline. At $1.50/L for its required 91 octane gas, that's $150.
Electricity is $0.08/kwh for the low tier where I live (Vancouver, Canada), so $4.80 to charge the 60kwh battery from zero.
The Bolt has an EPA range of 380 km. So, I was figuring that it would require two (and a bit) charges to hit the same 800km number.