Hi Adrian,
This really depends on how your screens have been customized. If you are creating an estimate from a Lead or Customer and you have chosen a specific "Price Level" option from the dropdown menu on either the Edit Customer/Lead Screens, then at this point, you have assigned a specific price level "name" to that Customer, which you can call from the Customer table.
To clarify the option for "Wait for sync Approval", the Estimate itself will not sync with Quickbooks until this option is unchecked. However depending on how the screen is designed, the information should be there without needing to sync with Quickbooks, for you to still make your custom price level calculations.
-Ben