You'd still get people flouting the law and people who just want cheap puppy who would over look the fact that the 'breeder' they were buying from had no liscence.
I've just heard about someone trying to rescue a dog to sell on
. The person trying to arrange the rescue had offered to pay the rescue fee for any potential adopter providing they passed the homecheck and interview because this poor boy only has until 3:30pm tomorrow to find a home or he will be killed. A 'dog dealer' tried to use this to her own advantage to obtain a free dog to sell 
I had no idea dog dealers existed but I have been assured they are quite common. And people wonder why rescues insist on so many checks and ask so many questions 