We find that certain consecrated objects can be redeemed and others cannot be redeemed; certain things that may not be eaten may be redeemed; things from which benefit may not be derived may not be redeemed. The nations of the world cannot be redeemed, as it is written (Psalms 49:8) "A man cannot redeem his brother; he cannot give his kofer to G–d. Too costly is their soul's redemption and unattainable forever."