The ISS dedicates more space to solar panels than radiators, despite the occupants having a very tight temperature requirement, which is about 20% cooler than the max most semiconductors can indefinitely run at. Just putting the radiator on the surface of the satellite might be enough, without even needing a panel.

Even if a heat radiator as large as a solar panel is needed, it'd be only a small portion of the overall cost.

Radiating waste heat on earth is a much more substantial portion of the total cost, especially so considering the social backlash it creates.