Well for me, I'm paying just over 22c/kwh, last period we used 808kwh over 80 days, so almost bang on 10 per day.
So with a solar setup that could charge a 10kw pack each day I could almost go off grid. That would save me nearly $1000/year once you take into account daily connection charges.
So the batteries would be paid off in 3-4 years, add a few years for however many panels I need and that's a pretty decent saving for no more power bills.
Of course it depends how long they are likely to last after that 10 year warranty period - no point swapping utility bills for tesla bills for replacements every 10 years.