Depends on who you invite. And the calligrapher's mentality is also very important. Although some calligraphers have great titles and high positions, they are always modest. They think their things are not good enough, or they think they are actually ordinary people. The appearance fee is not high. Some are the opposite.
I can give you a reference (I once invited a famous calligrapher, a vice chairman of a prefecture-level city, to give the whole activity to 2000. ) Of course, at the same event, I also invited a famous calligrapher to quote 2000 yuan for each work.