Increasing the Limit and charges

Increasing the service quota limits for Amazon EC2 resources through the Service Quotas console is not chargeable. When you request a quota increase, you are simply asking AWS to allow you to use more of a particular resource in your account. This increase in the quota itself does not incur any additional charges.

However, it's important to note that while increasing the quota is free, you will be charged for any actual usage of the resources once they are provisioned and used. For example, if you increase your quota for EC2 instances and then launch additional instances, you will be billed for those instances according to the standard EC2 pricing.

In the specific case of Elastic IP addresses, which have a default limit of 5 per region, increasing this quota does not automatically allocate new Elastic IPs to your account. The increased quota simply allows you to allocate more Elastic IPs when needed. You are only charged for Elastic IPs that are allocated but not associated with running instances.

Remember, it's always a good practice to carefully consider your needs before requesting quota increases, and to monitor your resource usage to avoid unexpected charges.
Sources
Cost Implications of Increasing Elastic IP Limits in AWS | AWS re:Post
Amazon EC2 service quotas - Amazon Elastic Compute Cloud