None. You can use solar panels for energy on Earth, and atmosphere is better for heat dissipation than the vacuum of space. That $10k cubesat (which, by the way

None. You can use solar panels for energy on Earth, and atmosphere is better for heat dissipation than the vacuum of space. That $10k cubesat (which, by the way, becomes much more costly once you add all the interesting stuff on it,) will have tiny solar panels, tiny heat radiators, and you cannot add much of a mining rig inside that 10x10x10cm frame. Not to mention that the orbit will decay in about 3-4 months.