Under the BYOL plan if you decide to not renew your licensing your allowable connections will revert back to 2 free trial mode but your servers will continue to run on your Amazon Web Services account unless you terminate them. So, you are never locked into Access Server licensing and can leave at any time.
Under our TIERED plan there is no licensing. The moment you bring down the AWS instance, you stop getting charged (hourly) by Amazon. So you can choose to stop and start the instance as needed and only pay for the number of hours the server is actually active and running.