Just to clarify a few things....
Properly licensed and permitted facilities(research, museums, public aquariums, etc,) may collect their own specimens under the specific terms spelled out on their permits. Any aquarium near the coast generally does this many times a year. However, it is not always feasible to do so due to location, season, or cost, so it is also routine to trade or purchase from other licensed facilities. Animals are frequently being traded back and forth and it's not uncommon for an institution to post on dedicated list servers any excess animals that result from successful breeding programs, or animals they may be looking to part with for various other reasons.
In lieu of that, the third option is to obtain animals from properly licensed and permitted 3rd-party exporters who go out and obtain the animals from the wild and then ship them globally to the reciever. These exporters are private individuals who are licensed by a country via permits to export specific animals around the world to institutions who meet specified criteria for ownership. It is usually a requirement for copies of both the exporter's and importer's permits to accompany the shipment throughout the process. This is something that is closely regulated by several organizations (at least here in the U.S.)
This is the route LBAOP took to obtain their Dragon's when they opened the doors back in 98. And AFAIK, it has not changed to date. The person who was responsible for LBAOP's breeding program and subsequent successful birthing/rearing of Weedy's was a former coworker and we talked at length about these very things on numerous occasions. At that time (2001-2003) LBAOP was the only institution who had a successful breeding program and there were probably no more then a couple licensed 3rd-party exporters working with the Aussies to export Dragons. This made getting them not just expensive, but a time consuming process. I know we treated our animals like gold because they were just about as expensive as the stuff.
I'm sure at some point they will be avialable within the hobby, at least on a captive reared level. My only hope is that when/if they do eventually trickle their way down to this level I serious hope that they command a price that will ensure only the most dedicated hobbist will own one.
Brett