Don't let these responses fool ya. Until recently the forums had threads like this all the time. The influx of RWS caps has changed that but for how long? And there are only a handful of places that have those. In my area I haven't seen caps of any kind in a shop or store in at least 3 years. Find them at gun shows with absurd prices on them. Only viable option has been to order online when a company I order from has them.
I doubt some of these guys noticed you're in Aus. as the responses to these queries have become copy paste and most don't bother to fully read them so an online place here in the U.S. is mostly useless to you. Sooner or later one of the more smug characters on here may well be inclined to inform you that they laid in a lifetime supply when things were good, so they don't know what you're problem is...