A Bill of Exchange (BOE) cannot be used to buy an item (car, house, stereo system, big screen TV, etc.).
A BOE can only be used to discharge pre-existing debts.
At this point, we believe that some sort of “loan” would have to exist or credit used to purchase the item and then a BOE can be used to discharge the “loan”. We say “discharge” rather than “pay” a debt because, since 1966, we have only had the ability to “discharge” a debt.
The basis of all “money” in circulation in Australia, since 1966, has been a Federal Reserve Note. A “note” is a debt instrument, a promise to pay. Common sense tells you that you can’t pay a debt with a debt (a Federal Reserve Note, or any other promise to pay).
The foundation of our ability to discharge a debt using a BOE is Bill of Exchange Act 1909 Cth. If you are not familiar with this legislation, you should study it thoroughly.