Recent advances in sensing and communication have paved the way for collective perception in traffic management, with real-time data sharing among multiple entities. While vehicle-based collective perception has gained traction, infrastructure-based approaches, which entail the real-time sharing and merging of sensing data from different roadside sensors for object detection, grapple with challenges in placement strategy and high ex-post evaluation costs. Despite anecdotal evidence of their effectiveness, many current deployments rely on engineering heuristics and face budget constraints that limit post-deployment adjustments. This paper introduces polynomial-time heuristic algorithms and a simulation tool for the ex-ante evaluation of infrastructure sensor deployment. By modeling it as an integer programming problem, we guide decisions on sensor locations, heights, and configurations to harmonize cost, installation constraints, and coverage. Our simulation engine, integrated with open-source urban driving simulators, enables us to evaluate the effectiveness of each sensor deployment solution through the lens of object detection. A case study with infrastructure LiDARs revealed that the incremental benefit derived from integrating additional low-resolution LiDARs could surpass that of incorporating more high-resolution ones. The results reinforce the necessity of investigating the cost-performance tradeoff prior to deployment. The code for our simulation experiments can be found at https://github.com/dajiangsuo/SEIP.