Hmm, I cannot imagine why it would cost $100K for a super charger unless they are for some reason much more expensive then regular chargers. And again the marginal cost per charger has got to be an order of magnitude lower than the first charger because trenching is very expensive but each parking space isn't very far from each other. i.e I'm guessing that putting a handful of superchargers in a lot of different places is much more expensive than putting a lot of chargers in one location.

In any case, I know that regular charger's are very simple they are really just glorified relays so it might make sense to use non-superchargers if they are actually much more expensive.

Sure most rental places aren't cash heavy ATM but they aren't the ones buying 100k Tesla vehicles.