2.5kW * 24 hrs * 182.5 days = 10,950 kWh for $100, or 0.9 cents per kWh, which is pretty good. And prices should go down as the technology gets improved, manufacturing gets sorted out, and economies of scale kick in.
If it works (still an if), it would be cost-effective enough to displace all other forms of power generation for new plants, and also be cost effective to retrofit existing plants.
>>And prices should go down..<<
I expect costs to go up as governments start adding in their taxes in an effort to balance their defective budgets.
I would think you need more than 2500 watts available around the house for running larger devices like freezers and fridges and washers and dryers and air conditioners. Ovens for cooking need a lot of energy. They need to have the ability to tap higher wattage numbers at least on startup.