Yeah, in an ideal world all things are possible. But still the powercell isn't going to be made for free. The sorium has a cost. The device has a cost. The reseller must make a profit. There must be certifications and inspections (on a yearly or more often basis). Then you have to dispose of the old one. You need back up power in the advent the thing fails. Also how big is this thing? Can you go down to wallmart and get it or does it have to be delievered by truck? All of this costs money, even if the power is relatively cheap on a per kWh basis.
Basically entropy always increases, there is no free lunch and perpetual motion machines aren't possible.
I don't see any of those things that can't be made cheaper or more efficient by technology or other products/materials with "magic-like" properties though.
The raw materials in use will be refined and transported cheaper and more effectively.
The device will be able to be built cheaper by more efficient factories.
The faster car/hover-car/plane/truck/trains making the delivery chain will get it further for less meaning less logistics and distribution costs in the lifecyckle per unit.
The size of it will very likely be smaller with more advanced technology (same as above less costs for logistics & handling), very clear real-world example is the minimum cost of a flat-screen compared to a older thicker screen TV/PC-monitor.
If it's to big for fetching with car you likely buy an installation for your house and refill it with fuel, if it's to big for truck you likely buy electricity per kWh from bigger installations like today, whatever is most efficient (whatever is most efficient = cheapest).