индиректно цената може да се сметне от това което дават като цена на произвеждания ток
200 kW мощност при $0.05/квч значи генерира енергия за $10/час за 40 години живот $3.5 милиона

noteworthy are the very strong Russian beta emitting strontium-90 sources used as thermoelectric power generators for beacons in lighthouses in remote areas

Electrical power is supplied by three radioisotope thermoelectric generators (RTGs). They are powered by plutonium-238 (distinct from the Pu-239 isotope used in nuclear weapons) and provided approximately 470 W at 30 volts DC when the spacecraft was launched. Plutonium-238 decays with a half-life of 87.74 years, [3] so RTGs using Pu-238 will lose a factor of of their power output per year. In 2006, 29 years after launch, such an RTG would produce only 470 W × 2-(29/87.74) ~= 373 W — or about 79.5% — of its initial power. However, the bi-metallic thermocouples that convert heat into electricity also degrade, so the actual power will be even lower. As of August 11 2006, the power generated by Voyager 1 and Voyager 2 had dropped to 290 W and 291 W respectively, about 60% of the power at launch. This is better than the pre-launch predictions based on a conservative thermocouple degradation model. As the electrical power decreases, spacecraft loads must be turned off, eliminating some spacecraft capabilities.