The cost of Blockchain Workbench is an aggregate of the cost of the underlying Azure services. Usage amounts and billing details for your subscription can be found in the Azure Portal.
HLF on AKS price also depends on the underlying services created with the service. See the below screenshot for example.
The solution template helps to deploy Hyperledger Fabric Blockchain network components such as Ordered and Peer organization on Azure Kubernetes Service. It provides the flexibility to choose the size and fault tolerance of the components. Hope this helps in answering your question!!