Where a broker foregoes a commission on a sale of land, as consideration for placing other lands in his hands for sale at a net price, he can not sue for breach of the second contract and rely on such released commission as damages, on the ground that the owner was estopped to deny that he was damaged to that extent. Shapiro v. Benenson, 167 N. Y. Sup. 1004, 181 App. Div. 19.

Where broker foregoes a fixed commission on a sale of land as consideration for an agreement whereby he is given the sale of other land, on refusal of the principal to perform the second contract, the agent could either disaffirm the second contract and be restored to the consideration parted with, or recover damages for breach of the second contract. Id.

Where a broker advanced money on a contract to sell land and the owner defaults, he can, on rescinding, recover the advance as for money had and received, but where, as consideration for the contract, the agent had foregone a commission due him on another deal, the action would be for the consideration parted with. Id.