the price is quite good
Average US residential power consumption 909 KwH per month.
That’s 30.3 KHh / day. These batteries are 7 KWh.
You get a few hours for $3K. Hell you get a few power outages a year of that duration, during which time you get in your car and go to a bar to watch TV or go to McDs and use their internet. Helluva lot cheaper than $3K for a battery that will need replacing (and btw, that 3K will have more tacked on for installation).
This is crap.