The cost isn't important, but for long term storage while not plugged in it is important. My i3, i8, Bolt and Leaf had negligible phantom drain, you could leave them 3 months at 50% charge with no issues. This is not true of Teslas, they have to be plugged in because they have drain that could empty a battery based on size and time. Older models are worse. If the battery fully drains and "bricks" you are done, you need a new battery. That would hurt.
Part of why this is important is you never want to leave a battery at full or empty for long period of time, so ideal storage would be around 50%. But if there is significant drain then you are either forced to fully charge before you store (full charge) or have it plugged in (remains full charge). The Tesla has a storage mode that maintains ideal charge if plugged in, but you have to have a plug where you store it.
I came back from one trip with my Tesla almost bricked because on a new firmware update something prevented the storage mode from kicking in the charger. I randomly checked and I was sitting at 7% in the red...I think I had one more week.
