Look at some of the research on the health costs of ICE emissions. Even before you try to assess the cost to the local and global environment you end up with annual death rates in the hundreds of thousands and many billions of dollars annually in medical expenses and quality of life reduction. A tax on pollution would be the best way to handle this since you could pour the money raised into healthcare and environmental remediation.
Even without taxes, I'm pretty sure that for most use cases, a good electric vehicle will cost a lot less in the long term when you factor in maintenance in addition to 'fuel' costs.