I've never heard of this brand - it looks like AVK Imports Australia have the exclusive importing rights in Australia - this is the wholesale arm of Guppy's.
Yes your right, Guppies online is selling it very cheaply.
I have just started using Seachem plus & trace and can only get 500ml bottles. With the dosing requirements on my tank I go through that in 5 weeks. Very expensive way to go, so I was offered it at almost half price from Andries at guppies. I have used guppies for years now with this tank and all the freshwater stuff I used to get. . I find he is very well priced and has always provided me with excellent service.
Do you know anything about the product, he says it is equal to seachem ?
I don't trust anyone without asking lol