C&E ACW buffs

A reader writes to tell me that James McPherson does not speak for free to civil war roundtables as suggested here, that he charges $1,000 (which is donated to Civil War Preservation Trust or another cause). He says, "The Chicago Civil War Round Table has been foolish enough to pony up," by which I assume he means they did not get $1,000 worth of value.
I believe he spoke for free to the Camp Olden Civil War Roundtable in 1999 or 2000. In any case, even if he charged $1,000 then, they raised $5,000 from the affair.
Which leads me to ask, in slangy terms, is there such a thing as a "Christmas and Easter" Civil War reader? Certain churchgoers are labeled "C&E" and I wonder if there is an ACW equivalent (one that would generate a $5,000 gate at a McPherson talk, for instance, then disappear).