Background and Objectives: Previous comparisons between right anterior mini-thoracotomy (RAT) and partial upper sternotomy (PS) for aortic valve replacement (AVR) have shown similar clinical outcomes. This study aims to assess the potential in-hospital cost differences in one technique over the other. Materials and Methods: Between 2018 and 2023, 303 patients at our institution underwent minimally invasive isolated AVR (241 PS vs. 62 RAT). Endocarditis, emergencies, and reinterventions were excluded. A 1:1 nearest neighbor propensity-matched analysis without replacement was performed. Perioperative clinical outcomes and hospital costs were analyzed, comparing total and average (per patient) direct, indirect, and total hospital costs between the two groups. Multivariable linear regression identified significant predictors of hospital costs. Results: Sixty-two well-matched pairs were analyzed. Significant differences were found in intraoperative (PS: 27/62, 43.5% vs. RAT: 10/62, 16.1%, p = 0.002) and postoperative transfusions (PS: 33/62, 53.2% vs. RAT: 16/62, 25.8%, p = 0.003), and median intensive care unit (ICU) hours (PS: 52.2 vs. RAT: 45.7, p = 0.007). Average direct, indirect, and total hospital costs were significantly higher for PS (p = 0.038, p = 0.040, and p = 0.035, respectively), with significant blood bank cost differences favoring RAT (p = 0.010). Multivariable linear regression showed that intraoperative and postoperative transfusions, ICU, and hospital length of stay were significantly associated with hospital costs, but not the surgical approach. Conclusions: PS and RAT have comparable perioperative clinical outcomes, with differences observed only in the number of transfusions and ICU stay, both favoring RAT. Given the significant perioperative differences and regression analysis results, the cost advantage of RAT is likely mediated through its impact on these perioperative outcomes.