[Panzer04]

The other replying commenter made a good point that "need" is perhaps not the best description, but I'll stand by it as reasonably close to what I mean.

Yes, there are plenty of people with high incomes who continue commanding resources they may not strictly "need", but across the economy as a whole the effects of these prices is still to allocate resources in an efficient way. The point is this avoids an acute shortage and rationing, which is the alternative to transmitting this information via prices and almost certainly far less economically productive.