I don't know what numbers you're running, what you guys are stating makes no sense to me.
Do anyone of you even touched a solar panel IRL? Seen one? Bought one?
I'm not sure how touching one would enlighten me about the numbers behind buying one but whatever.
In central EU it would cost me about $7200 to have a decent (5kw) unit that would provide me with 630 watts 0-24h on average.
Using 630 watts 0-24h with $0.14/kWh costs $760 a year so that's over 9 years before reaching ROI.
So yeah, you might be able to get your hands on some super cheap solar panels+inverter+batteries but I'd much rather pay the $0.14 with a grin on my face and spend that $7k on more hardware.