A: RONR doesn't really say much about budgets specifically. However, since by definition a budget is an estimated financial plan, it would seem to allow flexibility. Perhaps your bylaws or even tradition specify just how much flexibility there is?

I would think that if an unbudgeted item is desired, the organization should at least be made aware of the fact, and that spending on that item may (will?) bust the budget. At that point, they could move to Amend Something Previously Adopted (the budget), deciding what to cut and what to add. See RONR Section 34.