Board Thread:TV Show Discussion/@comment-1364745-20160524104605/@comment-114.71.100.55-20160525115844

Martin's rule is not always life for life. For general magic, the greater the magic, the greater the price and blood must be paid for blood. Even case of Daenerys, she paied blood but actually we don't even know she used the baby's life for reviving Drogo or cursing both Drogo and Daenerys. However, if it is power of God, the price is not always life since it is more of granting a wish then bargain. Even in the book, Thoros resurrected Beric Dondarrion several times and the price was part of himself not his life. Although Melissandre is not acknowledged prestess of R'hllor, out of desperation, she might have actually reached R'hllor and saved Jon.

However, I think Ghost should have died for Jon. It would make more sense since Mellissandre is only alleged priestess not real and blood for blood make more sense. In addition their soul is connected so it is a perfect sacrifice and the show doesn't have to pay hefty price for showing animal.