How the resellers billing order is generated? Where the prices, service descriptions are taken from?
When the resellers customer purchase some service based on delegated plan, the record to the "ResellerTrans" table are added. The records are added based on the information from the providers service plan, which means the price, the service plan name, description are taken from the initial providers service plan. The price is always taken from the price set in the providers plan on the moment of purchase, there is no need to synchronize any susbcriptions. That means that there is no possibility to "freeze" price for the reseller - to have one price for all the customers and leave a different one (e.g. initial when the resellers subscriptions was purchased) for the reseller. There is a feature request with id #PBA-61840 ("Freeze prices for delegated plans") to have such possibility.
At the billing day the billing order for all of the services provisioned is generated (based on records from the "ResellerTrans" table).