Daniel_G: I estimate the volume of reactant in your proposed reactor is approximately 3 L. Is that correct?
Experiments by Roulette and Pons produced 300 W/cm^3. At that power density, you would need only 200 cm^3 of reactant to produce 60 kW thermal. However, you would have to spread it out in something like thin plates, or the fuel rods in a fission reactor, or a fire-tube boiler. If the entire 200 cm^3 of material was lumped together, it would melt.
I predict that when the technology matures, decades after it begins, a 60 kW cold fusion reactor the size of a truck battery should cost very roughly as much as a truck battery. I say that because the materials will not be rare (I hope!), the mass of materials will be roughly the same as a battery, and the degree of precision, purity and cleanliness in manufacturing should also be about the same. Both batteries and cold fusion cells should be sealed units. The cold fusion cell should have enough fuel in it to last for the life of the machine. I suppose the life of a machine will be 15 years for most ordinary applications such as home generators or automobile engines. Maybe 30 years for remote application thermoelectric gadgets, for things like railroad crossing gates in the middle of nowhere in Alaska. In other words, the cell will be permanently sealed. It will not have to be opened up or refueled. I think that makes it cheaper, simpler and more reliable.