Eugene Plante was a general contractor who built a house for Frank and Carol Jacobs for a contract price of $26,765. The buyers paid $20,000 but refused to pay the balance, claiming that the contract had not been substantially performed. Plante sued, and the court ruled in his favor but first deducted the cost of repairing plaster cracks in the ceilings and a number of other defects. The buyers were dissatisfied with the judgment and appealed, notably because the trial court had allowed nothing for the misplacement of a wall between the kitchen and the living room. This enlarged the kitchen and narrowed the living room by one foot. Real estate experts testified during the trial that this did not affect the market price of the house, yet to move the wall would cost about $4,000. How should the appellate court decide? (Plante v. Jacobs, 103 N.W.2d 296, Wis.)