Export the sheet, edit it in Excel (prices, or add and remove rows), then upload it to review every change before anything is applied. Row order and the columns must stay as exported.
Change a price directly in the table, or add a row for a new component. Edited cells are outlined; nothing is saved until the changes are reviewed and applied with your password.
Every applied change keeps the version it replaced. Preview a rollback to see exactly what would change back; the committed file is the version in the repository.