lol - if it was that easy to bring in a fish EVERYONE would do it!
In the five years I have been involved in the Canadian arowana forums, there has been one guy I know of who brought back a fish from vacation, and he smuggled it. Not a wise move in my opinion.
The main problem concerns the logistics of getting the Vet cert needed for the Malaysian export CITES Permit, along with coordinating the application process for the Canadian CITES cert. If you were going for a super high end fish, say $3000-5000, then I would say you probably could find a store or farm willing to go through the trouble for you. In such a case you would either buy the fish blind way in advance from the store/farm and have your relative travel with it as checked luggage (remember no liquids allowed on planes now, fish would have to be in their suitcase), and this way save on the shipping cost. Alternatively, you could ask your relatives to choose the fish for you and then arrange for the store to ship the fish for you once the paper work comes through a couple months later (as a first time importer you will find the Canadian gov. takes its time processing your permit for your first couple imports). In this scenario you would be looking at a high shipping cost since the airlines have a minimum price for shipping the live cargo box. There are some other considerations too concerning the CITES permit process I have not mentioned that would also potentially complicate matters. Still, for a high value fish it is doable. If your relatives were staying longer, like say 2-3 months, it would make it a lot easier.
Anyhow, now you know why the group buy method came about! By cooperting together we get all the paperwork and shipping done for a group of fish - at a much better per unit price than what we would get individually. The group buy is all about pooling resources to get a better discount - on the fish, on the paperwork, and on the shipping.