Doing a total cost of ownership (TCO) comparison between your current petrol/diesel fleet use and a switch to EV might show there are no additional costs, so that’s worth doing first. If the higher purchase price of today’s EVs against petrol/diesel equivalents is a concern, don’t forget the lower costs or running and maintaining an electric vehicle.
There may be benefits beyond cost. As public pressure increases and economies around the world continue to de-carbonise, customers may favour businesses that have the foresight to adopt EVs early.