If we all waited for the latest and greatest to arrive we would never purchase anything........and there is currently an exemption from Road User Charges. That may not exist in 3 years time, but what is certain is it does exist now. And if we all bought cars based on some expected resale value in some predetermined time frame, we would be best buying collectibles only.
As for RUC, for someone travelling the average 12,000kms a year, that's $816 a year (in saving). Not a lot. Long term (accounting for the cost of vehicles, their currently development pace, depreciation etc) that's a drop in the pond.
And spend only $233.77 in electrical 'fuel' over that 12,000km, as opposed to $1948.80 in a petrol driven vehicle.