I gather that Tesla's model is also targeted at people who may also wish to start storing power they buy off the grid at times when the cost is lower (as well a

I gather that Tesla's model is also targeted at people who may also wish to start storing power they buy off the grid at times when the cost is lower (as well as from locally generated solar, turbines, etc). Price point commonality may be more coincidence than anything else. There's a philosophical question in there for some (probably small) number of customers -- whether they wish to remain beholden to vendors of electricity, at whatever rate is determined by the vendor at the time.