Amazon RDS is a fully managed database service provided by Amazon Web Services (AWS), promoting an easy way to set up, operate, and scale a relational database in the cloud. However, its pricing can be complex and costly, with various factors such as compute capacity, data transfer, storage, and technical support contributing to the overall cost. To mitigate these costs, it's essential to right-size instance types, optimize usage, monitor non-production environments, use the correct instance sizes, turn off idle instances, remove manual snapshots, purchase reserved instances, plan data transfer routes carefully, optimize database performance, and consider hosting on a different platform like Timescale for time-series and analytics workloads. By implementing these strategies, users can reduce their RDS costs and improve the overall efficiency of their cloud-based database infrastructure.