you start vale at 14 ... not at 18 this is why ...
cold iron makes more sense at lvl 6 because that is when you are in thernal, co6, and invasion ... these are the places you find the most reavers per level
bysheck as a side bonus would be ok but there are no missions where mindflayers require you use a dr bypass to kill .... there are no raid mindflayers ... and even if there where they wouldnt be a lvl 6 raid ... cant even think of a mission that a lvl 6 character would run that has mindflayers in it ...
lvl 10 for shrieking and lvl 14 pop (even though many do them at lvl 8 and lvl 10 currently)
still makes more sense to have sliver/crystal (for rusties) at tier II and cold iron/bysheck at tier I
that sets up transmuting or silver for tier III and makes the whole set useful at level for bypassing common DR's at lvl ...