Here is a person who installed a Power Wall 2. Cost $32,500 with 5kW of solar. So a 10kW install will cost around $65,000. Also, look at his roof install. Goofy! Not all of the panels are installed the same direction. Finally, 10 months to install.
https://youtu.be/6s6kN9Ezws0
We just did a Mi-Grid install. 10kW, with ground mount array (more expensive than roof) for $44,500. And Mi-Grid includes a 20kW backup generator. Signed contract in mid November and they were online before Christmas.
Oh, and in the video, he notes the system will not work in the event of loss of INTERNET access. So, won't work off-grid.