Reserved Instances typically offer significant savings over
On-demand pricing, sometimes up to 75%. However, they aren't always
the most cost-effective option for every scenario. RIs require a
commitment to a specific instance type and region for 1 or 3 years.
It can lead to wasted spending if your usage changes.
Thus, analyze your usage patterns and predictability of workloads
before committing to RIs. For fluctuating workloads, On-demand and
Spot Instances might be more cost-effective.