Nice idea, George. I will stay away from it though.
I stick to my limit number to keep the printing and finishing to a couple of days after work for each round.
Life otherwise gets in the way.
Living somewhere that has a discunted postcard rate would certainly help in sending out more cards.
I try to budget for the paper and postage, to keep each round at a bit under $100.
I have stuck with this for something like the last 15 rounds, so that formula seems to be working for me.