Tattered Cloth Vest has the highest item level here (2). The lowest listed price among them is Simple Black Dress at 75 silver in the US Auction House.
Karabor Priest's Tunic is part of the transmog set Karabor Priest's Vestments (Priest, Mage and Warlock only), which the Appearances collection lists in 2 versions. The other 9 pieces:
Blizzard numbers items as they are created, so the named items next to ID 234871 (234866 to 234876) were usually added in the same batch as Karabor Priest's Tunic: the same quest line, zone, vendor or reward set.