&gt; No, you could not. I can do it cheaper is distinct from I can do it for free.<p>No, its not. &quot;I can do it for free&quot; is an instance of &quot;I can do it cheaper&quot;. Its quite possible for someone to have a non-negative (zero or positive) net utility from an act which gives someone else a net positive utility, so that the &quot;price&quot; they are willing to charge for that task is zero or even negative (that is, they are willing to pay for the opportunity.) That&#x27;s no different than the variation in utilities between suppliers with a net negative utility who are willing to do the task for a variety of positive payments.