Have to agree. Love the design of the salt and pepper shakers. Gotta admire your honest approach in wishing to purchase a set. Have been on a couple of NZ flights in J/C and noticed a few customers taking a set of 'souvenirs'. I would guess that they are high on NZ's replacement list.
As suggested, I would wager a set would wind up on EBay. Anything and everything can be found there.