To control the cost of an AWS deployment and keep it within defined limits, service quotas (a.k.a service limits) can be used.
Storage
Quotas to storage used by EFS (disk) and RDS (database) can be set up according to this guide:
https://docs.aws.amazon.com/general/latest/gr/aws_service_limits.html
Load Balancers
Quotas for load balancers can be set set up as described in:
https://docs.aws.amazon.com/elasticloadbalancing/latest/application/load-balancer-limits.html
Note that when solutions are deployed on using EC Deployments (Execution Context Deployments (ECDs) (3.0)) these can include Load Balancer resources that will consume from the quota.
VPC
Quotas for VPC networking resources can be set up as described in:
https://docs.aws.amazon.com/vpc/latest/userguide/amazon-vpc-limits.html
MemoryDB
If MemoryDB is used to persist runtime state, its quotas can be configured according to:
https://docs.aws.amazon.com/memorydb/latest/devguide/quota-limits.html