I enjoy facilitation and also the preparation:
But I am used to do this as volunteer. So I am afraid I might spend too much time preparing if anybody was to pay for this. I take it, that longer workshops needs more planning, but maybe not proportional (for instance a two day seminar of 15 hours does not requiring 6 times as much planning as a 1,5 hours workshop - or?)
Do you have a rule of thumb for how much preparing for a workshop?