Here’s a discussion of the story, where the SF convention (the Eastern Science Fiction Association in Newark, NJ) in 1947 or 1948 figures in one way or another. Key quotes:
Sam Merwin, then the editor of the Thrilling SF magazines: "Around this time he was invited to address a science fiction group in Newark hosted by the writer, Sam Moskowitz. `Writing for a penny a word is ridiculous,’ he told the meeting. “If a man really wanted to make a million dollars, the best way to do it would be start his own religion.”
Sam Moskowitz (in a 1994 affidavit), "After speaking for about an hour at the meeting, Mr. Hubbard answered questions from the audience. He made the following statement in response to a question about making money from writing: “You don’t get rich writing science fiction. If you want to get rich, you start a religion.’”
Others, including Elron’s ex-wife and Theodore Sturgeon and Harlan Ellison, also report he was fond of making this kind of statement during the late 1940s and early 50s.
