AWS BOTO3 API: IAM user per region using aws:RequestedRegion global condition key or IAM user per account ?

[schau87]

I want to query all the important information from the following AWS services:

• EC2
• RDS
• ELB/NLB/ALB/ELBv2
• ECS
• Lambda
• SNS

These services are being used per region in a single account. Whats the best way to query it via the BOTO3 API?

Questions:

1. Shall I use IAM user per region using aws:RequestedRegion global condition key and then query it per region?
2. Shall I just create an IAM user (Global) and use this user to query all services in theri respective regions ?
3. Also from the cost perspective which one will be better ?