Is Amazon SNS cheap?

I'm curious about the cost-effectiveness of Amazon SNS when it comes to using it for cryptocurrency and finance-related purposes. Can you elaborate on whether Amazon SNS is considered a cost-friendly option for businesses in this industry? Are there any hidden fees or charges that we should be aware of? Additionally, how does its pricing compare to other similar services in the market? Ultimately, I'm looking for a comprehensive understanding of whether Amazon SNS is a financially viable option for our company's needs.