Your math kinda sucks... You need a $318 monthly plan, which is around $45 CAD per month. And you have to pay for the laptop outright - $3480 HKD (about $500 CAD). The $500 is "returned" to you in equal monthly payments over 2 years.
So really, it's not "free", it's subsidized over 2 years. And the monthly plan is only usable on the laptop - you can't take a SIM and stick it in an iphone or a 3G router or anything. So that's $1080 CAD going to a plan that is only usable on a single laptop. Which essentially is paying for the laptop as well, on top of the 2 year payment plan you are giving them.
Like most "awesome deals" in Hong Kong, this one doesn't stand up to scrutiny.
Also it's a POS with a crappy battery (about 2 hours). Take a look at a review of the Onkyo C204 it's based on (it's a shitty review, but you can get an idea of how it looks and performs):
http://www.youtube.com/watch?v=n3FxIFyl0zE