Here are the cards with their prices as of October 4, 2013.
-- means steadily decreasing
-+ means steady
++ means steadily increasing (because of use in other formats than Standard)
Falkenrath Aristocrat 3.85 --
Huntmaster of the Fells 4.54 --
Mikaeus, the Unhallowed 4.50 ++
Sorin, Lord of Innistrad 5.57 --
Avacyn, Angel of Hope 6.58 ++
Cavern of Souls 4.53 --
Craterhoof Behemoth 6.53 --
Entreat the Angels 7.06 ++
Vexing Devil 2.59 --
October 24, 2013 update: I have decided to skip a second M13 redemption and to go for second redemptions of DKA and AVR, as well as to set up DKA and AVR for third redemptions. For $17 to the bots I set up DKA and AVR with all commons, uncommons, and all but two rares ready for a third redemption.
Here are the cards that I need for the second and third redemptions.
Here are the cards that I need for the third redemption.
October 25, 2013: $2 for two of the DKA Mythic Rares in the 3rd DKA redemption.