>>5750485>>5750620My Broadsword's Master Chief came with a missing leg, MB replaced it and there were no other parts missing. I don't know about the set being less popular but I would guess a reason could be less "playability" for older collectors. Kids will love swooshing it around and firing the missiles at things but it's not very conducive to battlescape dioramas and photo ops.
It's also a lot less iconic than many other Halo vehicles, if I had to pick between it and say the Sabre for shelf display I'd definitely go with the Sabre, heck even the Seraph is more notable to me but then again I haven't touched Halo 4-5 yet (and I'm not sure I ever will, 343 are bastards).