From this article on the subject:
-- Sam Merwin, then the editor of the Thrilling SF magazines: quoted in Bare Faced Messiah p.133 from 1986 interview. Winter of 1946/47.
"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.'
To summarize: we have nine witnesses: Neison Himmel, Sam Merwin, Sam Moskowitz, Theodore Sturgeon, Lloyd Arthur Eshbach, Harlan Ellison, and the three unnamed witnesses of Robert Vaughn Young. There is some confusion and doubt about one of them (Sam Moskowitz). Two are reported via Russel Miller: one is reported via Mike Jittlov: one reported in his autobiography; one reported in an affidavit; and one reported to me in person. The reports describe different events, meaning that Hubbard said it perhaps six times, in six different venues - definitely not just once. And the Church's official disclaimer is now reportedly a flat lie.
It seems it was discussed. However, would LRH have written such a story, it would quite certainly have surfaced in the process against Stern:
Now, there is a problem with the three Moskowitz reports. Specifically, the Church obtained affidavits in 1993 from David A. Kyle and Jay Kay Klein. Both names are well-known in science fiction, and both say that they went to the 7 Nov 1948 talk by Hubbard. Both say that they didn't hear any such statement. Puzzling.
I believe that these dueling affidavits have met in court. Stern, a German magazine, was sued by the Church, and the suit was thrown out of court after they obtained the Moskowitz affidavit.
Having a story of LRH would've been an even better proof and we can therefore assume it doesn't exist as Stern would've probably found it in their research.