In that article they claim the digit of $200, while you can buy an assembled 1kw/h battery pack in China in retail quantities for around $120 today.
Typically grid storage batteries are rated to 10+ years or ~5000 cycles or something on that order of magnitude.
One way to get your cells to last that long is to lessen the discharge depth; that may account for some of the price difference.
In that article they claim the digit of $200, while you can buy an assembled 1kw/h battery pack in China in retail quantities for around $120 today.