"We are justified freely by His grace through the redemption that came by Christ Jesus." (Rom. 3 v.24)
The word "redemption" means to deliver someone by the payment of a price. In this tableau, we're at the slave market - and you are the slave! You are about to be sold into the slavery of a life of sin, but Jesus comes along and offers to set you free. However, in order to set you free, He has to pay a price for you. That price is your redemption. What price did He pay? He paid Himself. He came into this world to offer His life and He came to offer His death. There was no higher price that the Lord Jesus Christ could pay.