I monkey around a LOT on australianhunting.net, and trust me, they know the differences between Benchmarks, etc. Most all of them can tell which Hodgdon powder belongs to which ADI number (2206H=H4895, for example) Heck, I'm getting so I know a few

, even. ADI's website has conversion chart with the powders, so when I recommend something for the .204 to one of them, (using H-322, for example) they can run to the ADI website, check the chart, and know to use 2219? (hey, I don't know them ALL!)
Actually, Hodgdon buys all the "Extreme" line from Australia, they mostly IMPORT the stuff, and until they bought the Winchester powder line here, bought the spherical stuff from Winchester's maker (Primex). The powder market is really interesting, if you're a nut about such things. Alliant Techsystems is really interesting, too. Not nearly all of it goes to reloaders, either, military and commercial explosives probably make up the majority of their business, from artillery stuff to demolition charges.
The Aussie reloaders are just as knowledgeable as US reloaders, maybe more so, since they have to really study up on stuff before ordering it, from US suppliers (they don't have the market we do, and no one gears up to make reloading stuff, except Simplex, maybe, so they have to import it, often on their own hook!
As far as ADI powders being less expensive than US powders, remember that the transportation costs are somewhat less, since they don't have to move it as far. However, when the US$ is strong, their costs are pretty equivalent to ours.
They don't get all the ADI powders, either, some are basically made JUST for Hodgdon, and vice versa, we don't get all ADI has to offer, either, so they get some stuff we can't. No matter, they seem to get by really well. Since we almost share the same language, it's fun to hang around with them.

Build a man a fire, and he's warm for a day. Set a man on fire and he's warm for the rest of his life!