The Massachusetts Bay Transit Authority (MBTA) awarded the Perini Corp. a large contract to rehabilitate a section of railroad tracks. The work involved undercutting the existing track, removing the ballast and foundation, rebuilding the track, and disposing of the old material. Perini solicited an offer from Atlantic Track & Turnout Co. for Atlantic to buy whatever salvageable material Perini removed. Perini estimated the quantity of salvageable material that would be available. Atlantic offered to purchase “all available” material over the course of Perini’s deal with the MBTA, and Perini accepted. But three months into the project, the MBTA ran short of money and told Perini to stop the undercutting part of the project. That was the work that made Perini its profit, so Perini requested that the MBTA terminate the agreement, which the agency did. By that point Perini had delivered to Atlantic only about 15 percent of the salvageable material that it had estimated. Atlantic sued. What kind of contract do the parties have? Who should win and why?