The rising demand for agile, economical, and scalable manufacturing has driven the need for innovative approaches in tool and die development. Aluminum has emerged as a promising alternative to traditional die materials due to its low density, excellent castability, thermal conductivity, machinability, and recyclability. This study proposes and validates a structured framework for the development of low-cost aluminum dies using Rapid Investment Casting (RIC). The framework, grounded in an extensive review of existing practices, is implemented through a real-world case study focused on the development of a die for an automotive door handle. A CAD model was designed with a 3%-dimensional tolerance, and the die was fabricated using LM30 aluminum alloy via RIC. The die was then tested using polypropylene (PP) in an injection molding process to evaluate its dimensional accuracy and surface roughness. Results revealed that in contrast to certain features, which exhibited strong dimensional consistency—such as the circle diameter along the large pin, front lengths, and upper slope depth (with deviations within ±0.1 mm to ±0.2 mm) some geometries, particularly sloped features, showed notable discrepancies. Small slope length 1 demonstrated a significant reduction of 0.66 mm during casting, likely due to angular mold erosion or material pullback. Additionally, the small and large mounting pin lengths, handle length, and small slope length 1 recorded the highest dimensional deviations. Despite these variations, the aluminum die achieved a surface finish near the industrial standard of 3.2 µm, while the molded PP part exhibited improved surface quality. Economic considerations reveal the saving of time (~7 to 3 weeks) and cost ($720 to $180). The results demonstrate that the proposed RIC-based framework provides a cost-effective, efficient, and flexible solution for producing customized or low-volume dies, offering reduced tooling costs and faster production cycles while meeting the industry standards.