That's because the OP has stumbled on the wire breaker & you have one of the patterns of wire cutters. Same purpose but entirely different piece of kit. I have had a number of sets of wire cutters & still have three (one is a relic set that I literally picked up myself on the edge of a field on the Somme about eighteen months ago), but I only have the one wire breaker, & have only ever had the opportunity to buy the one.....they are seriously rare. Wire cutters are scarce, but relatively speaking, much commoner. The luminous sights again, are scarce, but like the wire cutters, do turn up from time to time. I have had several sets over the years but have only kept one. I really have no idea on values, especially outside the UK, but no doubt somebody will be able to advise you.
Incidentally the wire breaker fits over the SMLE bayonet & the two 'jaws' hold the strands of barbed wire in front of the muzzle of the rifle. Firing a round of course will then shear the wire. Lord knows how long it would have taken a Tommy to get through a 50m deep obstacle on the Hindenburg Line! (& whilst being shot at).
Nice find!