Inventory Used transactions are not included in Time & Materials billing.
User bug report.
Make a report of the Inventory Used items used on the project, and enter a Billing Record-- Misc. Charge for the costs.
Starting with Goldenseal accounting software version 4.5, the T&M Billing correctly includes Inventory Used transactions for the project.
Programmer note-- code changed in CExpenseTransaction::AdjustJobCosts