Announcing the new pricing plan for AWS Config rules

Effective August 1st, 2019, AWS Config rules will switch to a new pay-per-use pricing model, lowering the bill for almost all existing AWS Config rules customers. In the new pricing model, you will be charged based on your monthly AWS Config rule evaluations. This new pricing is designed to provide almost all of the current AWS Config rules customers with a significant reduction in their AWS Config rules bill.

Source: aws.amazon.com