I haven't bought QSL cards in over a quarter century. I print them at home on card stock. Yes, this is a relatively expensive way to do it but for the handful per year I typically send out, it works. I'm not stuck with the same design for a decade or more, I don't throw any out for an address change and I can make custom cards for any event/occasion.
Mark K5LXP
Albuquerque, NM