Is helium-3 a viable source of energy and worth taking a trip to the Moon to mine?

Helium-3 (He3) is gas that has the potential to be used as a fuel in future nuclear fusion power plants. There is very little helium-3 available on the Earth. However, there are thought to be significant supplies on the Moon

At $1400 per gram, one hundred kilograms (220 pounds) of helium-3 would be worth about $140 million