If a person was makdish [made holy] his properties and amongst them was wine, oil, or birds, they should be sold to the people who need them and the money should be used for karban olos.

Shikalim 4:9

The cohanim used to buy flour and oil in advance, a month ahead of time. The seller did not get his money until the korban is brought and atonement happens.

If the price went up or down the seller would have to eat the loss. If the flour or wine got ruined, the seller would also take the loss.