New Civ game, same suggestion

For some reason with intro of Civilization V the developers at Firaxis decided to no longer make commodities subject to trade even though they were in Civ IV. Once again fix this and make them subject to trade. Wheat, Rice, Crabs, and Fish should be subject to trade, whether it is based on how many titles of the resource you have or the number of in said tile they should be on the table for other civs to want and exchange for other resources and luxuries. It adds depth to the game but also balances civs out that don't have access to resources whether strategic or otherwise.