I was looking at lipo's last night. Still over 4x the cost of lead acid. I got my batteries @ ~$100/kwh. That's roughly the cost at a few places I've looked: walmart, costco, golf cart and auto repair shops. And that's with lifespan et al factored in.
I don't think what you said is true. Either you have not thought out what you posted and have not done the correct calculations, or you are just making it up. Here is an actual price comparison between lead acid batteries and Li-ion batteries. To summarize, lead acid batteries cost 0.76€ / kWh / cycle, while Li-ion batteries cost 0.42€ / kWh / cycle. That is, lead acid is 81% more expensive per kWh/cycle than Li-ion. In addition, lead acid batteries are bulky, stinky, heavy, and don't last very long. That means you will have to lug them in and out of your house with far too great a frequency, and doing so will not be fun.