Justinmetals, you must be a relative newby to this thread.
"dulla fiddy" was a pie in the sky speculative term for $1.50 SP when Arrowsmith was being drilled and flared.
That SP was never really a possibility, however the term stuck anytime that someone got excited on news and speculation got ahead of itself. In this case, Potts was just having a bit of fun to rekindle the memory.