7 Wonders Resource Clarification
This question indicates a common misunderstanding of the way resources work in 7 Wonders. Resources are not collected and spent; you can build any card (building or Wonder stage) that requires resources as long as you have your own access to those resources, or pay a neighbor for the temporary use of theirs. If you do not have the required resources, and cannot acquire them from your neighbors, you can't build the card or Wonder stage.

Coins work differently as a building cost; when they are required, such as for the brown split-resource cards, they are paid to the bank.