If you don't need the granularity, you can store all the credentials that will be used by a specific caller(s) in a single JSON object and it will cost you only those $0.50. You can easily fit a thousand, maximum size is 64kb.

DynamoDB also makes for a nice fine grained secrets manager with their new table resource policies: https://speedrun.nobackspacecrew.com/blog/2024/06/27/using-d...

I use Parameter Store instead