doberden,
In this case the agents and developers are one and the same, so it's not a question of commission but net profit. Average profits on a new build are @ 40%. At Humber Valley I suspect the margin is greater as I was told they got the land very cheaply because they were creating jobs in the poorest part of Canada. So, they've sold this particular property to an 'investor', who is also paying service charges every month. They have little if any incentive to resell it; there are much greater returns to be had by selling the new build, rather than a resale.
As For DonKing's suggestion of using a local agent I suspect they wouldn't touch it as the prices are totally out of alignment with the local area.
This is all yet another reminder to do exhaustive research before parting with your money, particularly with regard to your exit stategy. You should know how you are going to dispose of your investment - at a profit, hopefully - before you buy. Not trying to teach people how to suck eggs, but in this case here were two more reasons I didn't invest; the developer having first call on marketing resales, and local comparables; Humber Valley is very much a top end development, located in a financially bottom end area.
Location, location, location.
I do hope viztopia managed to sell successfully.