Then they will LEAVE the market to those who CAN make a surplus---or go bankrupt (same difference).
Don: Yes. But your belief that a price war would errupt in the original "candy bar" scenario is not correct. If there is sufficient demand, there is no reason to engage in a price war. Indeed, a price war would just eat into profits. The price war only makes sense if the market is saturated with candy (supply exceeds demand), and you need to undercut your competition to sell your product.
Monopolies and cartels are EXCEPTIONS to the Labor Theory of Value---but they do not (repeat: do not) bring ANY additional wages to the WORKERS.