Unless you mean, say, production of ionizing alpha radiation, capture and containment, in which case you're using up another scarce resource of radioactive source products, generating far more radioactive waste then existing dirty nuclear plants, all for an amount of helium that you need a laboratory to measure.

Or maybe you mean by fusion? In which case you'd need a fusion reaction which yields stable helium isotopes which can be extracted without including radioactive byproducts. The difficulties here make interplanetary trade seem like nothing.

Economics is not a magic bullet. You actually need viable choices first, which we don't have here.