You can not generalize ... it depends a lot on each one, from his point of view ...

In these times, for example, if one has invested in photovoltaic panels or even another regenerative energy source (water, wind) ... the return with direct energy sales is even lower. So this is the last chance to consume it with the mining to earn more, compared to direct selling ... where they give a poor value of 2-3 cents per kw ...