At the price of $ 100 there is an excess of supply.
That means the price is above the equilibrium price.
The price of balance is practiced when the quantity of shoes offered is equal to the quantity of shoes demanded. That is, when the equilibrium price is practiced, there is no oversupplied or suppressed demand.
However, when the price is above the equilibrium price, the bidders are encouraged to bid more, as is the case for this exercise.
On the contrary, if the price were below equilibrium, consumers would demand more, but shoe producers would offer less.