Nearly abandoned heavy oil reservoirs present significant challenges for effective reserve utilization using conventional development methods. In-situ combustion technology emerges as a promising solution to enhance recovery from such reservoirs, although its widespread adoption is hindered by high investment costs and economic inefficiencies. This study employs a break-even model and sensitivity analysis within a volume-cost-benefit framework to explore the equilibrium between oil production costs and revenues under varying oil price scenarios from a multidimensional operational perspective. This approach clarifies the critical economic indices of fire-flooding operations and aims to optimize production operations and decision-making effectiveness. The findings reveal significant gaps in pre- and post-operation understanding of the reservoir, where inputs often surpass outputs, coupled with a lack of clear control strategies. These factors contribute to the low cost-effectiveness of in-situ combustion and insufficient grasp of sustained development and operational risks, ultimately impacting investment decisions in reservoir development. The study not only directs improvements in operational efficiency for in-situ combustion but also offers technical support and introduces new management strategies for the effective development of nearly abandoned heavy oil reservoirs.