I've decided to invest for a pre-selling condo and currently comparing offers from different agents. While all of them are offering the standard promos, there are some who are also willing to give their commission as discount.

I'm a bit confused because there are some who include the commission in computing for the net TCP (lowering my monthly DP outright), while there are some who say they can just give their commission once they have receive it in tranches. The first option is definitely better, but I'm not sure if that's really how it works. On the other hand, how do I guarantee that the agent actually does remit to me once they received their commissions?