Hydrogen leaked into an enclosed space is dangerous.
Ammonia is very bad for your lungs.
As for costs of your vehicles, you need to consider wearout of batteries, some have short life. Hopefully getting longer, need solid warranty plus recorder to prove you didn’t leave it sitting for two weeks in a low state of charge. (Some Tesla fools found that after driving to the airport then flying out on vacation they had an expensive brick.)
As for ‘zero emissions’ that’s a scam that omits emissions in mining and manufacturing.