Under a real estate brokerage contract giving the broker a commission of 20% of the list price and one-half of the overage on the prices obtained above the list price, broker is entitled to his full compensation when 3/4 of the collections are sufficient to pay them, though the collections to that time are not equal to the list price. Hopewell Heights Dev. Co. v. Kagey-Marshall Realty Co., 102 S. E. 582, - Va. Sup. - .