Murabaḥah is a term for a sales contract where the buyer and seller agree on the markup, the ratio between the cost of a good or service and what?
Markup (business) Markup is the ratio between the cost of a good or service and its selling price. It is expressed as a percentage over the cost. A markup is added onto the total cost incurred by the producer of a good or service in order to cover the costs of doing business and create a profit. The total cost reflects the total amount of both fixed and variable expenses to produce and distribute a product. Markup can be expressed as a fixed amount or as a percentage of the total cost or selling price. Retail markup is commonly calculated as the difference between wholesale price and retail price, as a percentage of wholesale. Other methods are also used.
McNamara–O'Hara Service Contract Act The McNamara–O'Hara Service Contract Act of 1965 (SCA), codified at  /351 §§ 351 –/358 358  , requires general contractors and subcontractors performing services on prime contracts in excess of $2,500 to pay service employees in various classes no less than the wage rates and fringe benefits found prevailing in the locality as determined by the United States Department of Labor, or the rates contained in a predecessor contractor's collective bargaining agreement. This is also known as the prevailing wage.