I would not worry about that. The absolute biggest cost is the battery and that decreases over time. 8/100k warranty on that. And second biggest cost is the motor which can fetch 2-3k and is warranted 48 months/50,000miles, third is HVAC.
After owning a 2017 Chevy Bolt with 300k miles and only changing the tires and coolant, then trading up to an ID.4. Worrying about repair costs should be the least of your concerns in these vehicles. Heat is the number #1 cause of premature failure of components, EVs can't produce anywhere near the heat of an ICE engine.
I think most here and a majority of ID.4s are still in warranty for the most part.