Sam, a plumber, entered into a contract for $75,000 with Orr, Inc., to perform certain plumbing services in a building owned by Orr. After Sam had satisfactorily performed the work, Orr discovered that Sam had violated the state licensing statute by failing to obtain a plumbing license. As a result, Orr refused to pay Sam. The licensing statute was enacted merely to raise revenue for the state. An independent appraisal of Sam's work indicated that the building's fair market value increased by $70,000 as a result of Sam's work. The cost of the materials that Sam supplied was worth $35,000. If Sam sues Orr, Sam will be entitled to recover: