Nurseswim:

The least valuable, given that condition is identical, type of Heer dagger would be one without a maker mark.

Things that add value would be rarity of maker, type of grip (true ivory would add hundreds if not a thousand dollars to the value) and embellishments (engraved name, engraved blade).

Of the three that you list here, the least valuable from a collector view would be the unmarked one, the most valuable would be the WKC with engraved crossguard. This of course all assumes that the engraving is period and the components of the dagger (the pommel, the grip, the crossguard and the scabbard) all belong together for that maker.

My 2 cents worth.

John

Always looking for Eickhorns and etched bayonets.