I was in touch with Glasshouse Works a few weeks ago and
inquired about Nepenthes, among other things. Yes, they sell
cuttings without roots. They also will root cuttings to order, and
that's why it takes so long to get one from them.
I have had bad experience with trying to root cuttings that
have been sent to me, even by 2nd day priority mail. They just
don't seem to root. The cuttings usually remain green for weeks
thus bolstering my hopes, but a high percentage simply turn brown
and die after 4-6 weeks.
I've had better luck when people have sent rooted cuttings
to me. If I want to root a cutting from one of my own plants I
usually follow the instructions in Pietropaolo's book. I've found
that placing a cutting in damp whole sphagnum in a tray, enclosed
in a translucent white trashbag usually works well. The entire
arrangement is placed in a sunny window, and temperatures are
not allowed to climb too high. The translucent trashbag admits
sunlight but not so much that the plants cook.
Good luck.
Perry