So your conversion starts this weekend, right? Solar is not mainstream by far but it is catching on, especially in states that subsidize the cost. Another thing to keep in mind is that a solar PV is terribly inefficient to use for heating your home. For that, a solar water heater is cheaper and more practical. So a true 100% solar home would use systems, one to power the lights and appliances and one to heat the home. Maybe that’s another reason for your $328,000 estimation.
I know of this guy in Charlestown, RI that installed a grid-tie PV system (he still uses oil to heat the house). Install price was about $20,000 but with the state's rebate and tax savings, the net cost was around $12,000. His payback is about 10 years, assuming the cost of electricity remains the same, which we know won't. $12,000 is still a lot, but if you plan to stay in your house a while, it can be worth it. Residence in other states like CA, have seen payback in less than 5 years.
Recently, scientists have discovered a way to capture infrared light (before now, it was theorized as impossible!). This type of plastic solar cell is much smaller (utilizing nanotechnology), more efficient and cheaper to produce. A PV system is about 12% efficient but an infrared is about 30% efficient. And like paint, this plastic cell can be sprayed on a wide array of materials, creating a highly portable and flexible solar panel!
Hopefully, it will be available to the public in less than 103 years