Is $9,000 to add a Powerwall expansion pack a fair price?

My wife was extremely against solar system due to aesthetics, so panels were installed on the east side, limiting full capacity compared to west/south facing installation. During the first week, I monitored the system and realized it generated around 6kwh from 8:30 am to 1 pm, then slowed to 3kwh from 2-4 pm, and less than 1kw from 4 pm. The Powerwall charges 30-80% and discharges from 2 pm until 5% around 6 pm. From 6 pm until the next morning, it pulls fully from the grid. I got into a Green Mountain 8 pm-6 am free plan for 24 months, which allows me to charge the Powerwall 3 during the night and go off-grid until 6 pm. From 6-8 pm, I spent around 8kw from the grid, which I assume will increase during the hot Texas summer. I am concerned about relying on "night free" plans for solar owners for the next decade and if these plans will disappear, which would make getting an additional battery less beneficial.