Seems like a good product and company. Unlike some other supplement companies they actually tell you what is in their supplement and the ingredients list seems to contain things that actually have some scientific evidence for working.
From the website:
An honest and useful pre-workout. Core ingredients that do just what you need and nothing you don't. No proprietary mixes.
From Facebook:
As always we love sending out samples, shoot us a PM if you'd like to try Tier 1. (comments confirm they send to Australia)
Update: Citadel responded to say that $5 shipping applies.
What happens at tier 2?