Hi Ozzie, welcome to the forum,
That's an interesting idea, but finding a supplier who sells second hand products like that isn't going to be easy I wouldn't think. I certainly have no clue whatsoever, but perhaps liquidated stock is your best bet.
You could also try wholesale auctions, liquidation.com for example. That's just a suggestion, not a recommendation and if you do use them, make sure you read the terms and conditions and research the sellers as well as possible, because dealing in a supply market like that has plenty of pitfalls you have to be aware of.