Do U All Think I Need To Pay The Agt?

One of the unit that I nearly close the deal... the seller didn't sign exclusive with any agent... he only told ALL agents that whoever sold his unit... he would pay them 0.5%... my agent still advertised for this unit... and brought many buyers to view the unit too...

Yes, I've heard of this in practice also. I was tempted to do the same when I wanted to move house.

There are rookie agents who are desperate enough to close such deals, but they must be informed beforehand what's in store for them.

Like what you said, there will be no exclusivity, whoever has the ability to secure the highest price for the unit gets the deal. That can be done, provided they know the rules of the game, what they stand to gain or lose, then let them decide if they want to be part of the game. If it's all agreed upon, then there's no reason for any the agents who lost out to seek compensation from the houseowner