You use the hybrid system every time you are in the car. You may not have used the plug but the battery/motor are integral to the vehicle moving on every hybrid plug-in or not.If you never plugged it in, just get the ICE version. LOL
I imagine we're talking potentially a decade of driving to cover the cost difference. Imagine doing that and then your hybrid system (you never used)? fails. Good luck on the resale.
Time to payback depends on how much you drive. On a city delivery vehicle, I wouldn't be surprised if payback was a year or two as you are buying less than half the gas of the ice sibling (assuming one exists).