Sold to whom? If robots end up making it so that no one can afford to pay for anything, then robots are not the most profitable option, is it.
Already discussed in another thread - robots don't require health insurance, social security taxes, can work 24/7 in cold dark rooms therefore at some point they will be cheaper than human workers no matter how low wage they receive.
Communist countries in recent times have been creating totalitarian states under the guise of economic communism, which was always doomed, because economic communism is only possible when all humans work the same amount (ie, nothing) due to the pervasive human notions of fair effort.
Don't confuse communism and socialism. The last requires only public ownership of the production means with central planning, however still allows
fair and reasonable wage differentiation. Some its form is our inevitable future in heavily automated world which is coming!