Consignment

Consignment is an arrangement where a dealer sells a watch on behalf of its owner and pays the owner an agreed amount after it sells, instead of buying it up front.

For the dealer, consignment avoids tying up money in inventory and removes some ownership costs, so you can usually offer the owner more than you'd pay outright. In exchange, your profit depends on the sale, and the owner waits to be paid.

Put every consignment in writing, and check whether your city's secondhand-dealer rules cover goods you receive on consignment.