The panels used in the solutions I've seen we're only 30% cheaper then the eu brands. But maybe they are a lot cheaper in the US.
I have seen cheaper panels on eBay, so I figured that the installer charged overprice for them.
I ended up buying a solution with eu panels which also had 12 years warranty and 10 years on 90% effectivity and 25 years on 80%.
Since we have one of the highest electricity price in the world, they have paid for them self in 8 years. Including the loan.
Right now the banks have "energy saving" loans at 4,8%. If paid back over 10 years, it costs nothing to install the panels in the monthly budget and then you still have at least 15 years of life in them. The inverter might need to be replaced.
We are 2.5 million households in the country and the organization that coordinates the infrastructure between the electric companies are receiving 150 applications pr day for micro PV Installations where you can use the grid as a battery.