With reference to brownfield sites redevelopment interventions, an innovative model for the definition of effective and financially sustainable initiatives is proposed and tested. The model borrows the operative logic of the break-even analysis (BEA). It neglects the basic assumption of BEA related to revenue linearity, by considering the real trend of the revenues. In fact, in specific contexts characterized by a real estate over supply—e.g., in small urban centers, or where a new plan includes a relevant increase in new buildings and/or the functional reconversion of existing disused complexes—the BEA hypothesis on revenue linearity could be inconsistent, as prices will tend to become depressed. In the mentioned situations, discount mechanisms on the unit prices could occur. These phenomena determine a reduction in the unit selling price in correspondence of the amount of gross floor area (GFA) increase. Taking into account the current and cogent needs of effective strategies for brownfields renovation, the innovative evaluation model is developed for supporting public and private investors’ decision processes. It could represent a valid reference in the preliminary phases of decision-making processes for public and private subjects, able to ensure the break-even point of the initiative balance sheet is reached.