You have a car with a 200 mile battery. You have a minimum threshold that you'll pay any price for (say 80 miles), and if your a miser / want a deal / want a sale , you'll let your car be charged opportunistically when it's cheap for the rest of it.

If you know your going to be parked at the office for the most part for 8 hours a day, then you'd probably be ok putting your car in opportunistic mode as long as you have enough for your commute.

The car can also track your driving patterns and manage all of this seamlessly. Having worked at a gas station and seeing how people swarm my station when gas was $0.10/litre less than the surrounding stations because we didn't update fast enough, I think there will be plenty of price chasers for these modes.

The anxious / I drive for recreation types / road trippers can pay extra to stay topped up all the time.

I don't know about you but the number of times I had to drive my car until the tank is empty on a whim is pretty close to zero and even if I was stuck with an EV and I had to suddenly drive 300km I could always just go to a fast charging station to charge the car quickly.