Patrick, I did not say you'd save the original cost, just the cost of a new pack.
Using the RAV4 EV and the ICE powered RAV4, and compare the costs for 100K miles:
RAV4 EV has a range of 80-120 miles on it's 27.4kWh NiMH battery pack, and cost about $3 to charge the pack, so
~100miles per charge = 1,000 charges x $3ea = $3,000 for electricity, and $0 for regular maintenance (on the EV drivetrain).
Being fairly generous, the ICE RAV4 can get 25mpg (the actual average of the 6 listed in the EcoModder Garage), so it would burn 100,000 / 25 = ~4,000 gallons of gasoline x $2.75 gallon = $11,000 (if you get 22mpg which is the average EPA Combined, the cost goes up to $12,500 - a increase of $1,500 for the 3mpg drop...)
The difference in energy cost is $8,000. Now for the maintenance, at the dealer:
Minor Service every 5K miles = ~$50 (I actually just paid $63.79 for my Scion xA) x 13 = $650
Intermediate Service every 15K miles = ~$150 x 3 = $450
Major Service every 30K miles = ~$450 x 3 = $1,350
Total for regular maintenance = $2,450
So the total cost difference is $10,450 per 100K miles.
There is also likely brake service on the ICE (EV's use regenerative braking and probably would not), and/or transmission/clutch service, too. The common costs would be for tires, and things like wiper blades, and washer fluid; and so these more or less cancel out.
Now the batteries will likely last longer than 100K miles -- say 150K-200K would be very possible, so adjust the cost savings accordingly: $15,675 - $20,900
plus any major repairs on the ICE drivetrain.