Cost estimation is a crucial dimension of architectural design. Typically, the accuracy in cost estimation progresses from ballpark figures and rules of thumb in early stages to precise quotations as construction starts. Additive manufacturing enables a new approach to project budgeting, as precise costing can appear very early in the design process and provide feedback to the designers when the project is still at a stage where changes are easy and inexpensive to implement. This chapter discusses the new, biunivocal relation between geometry and costing when 3D Printing is incorporated in the design process, and the influence of real-time costing brings to the decision-making process. AirLab’s project v-Mesh is presented as a case study.