Anthony Nugent, 57, was shot and killed in front of his partner in his apartment at Hamilton South, Newcastle, in September 2022.
Mohamad Raad, 45, Mohd Azlan Latham Aznan, 29 and Tyrone Tuli, 29, stood on the other side of the door as shotgun pellets ripped through the dealer's chest.
They have each pleaded not guilty to murder as their NSW Supreme Court trial opened in front of a jury on Wednesday.
Prosecutors say Raad pulled the trigger of the shotgun while the other two agreed to the murderous plot through a joint criminal enterprise.
The violent shooting took place just over 24 hours after Mr Nugent and another man arranged to sell a gel blaster under false claims it was a real pistol, jurors heard.
The buyer - who cannot be legally named - is expected to testify that he wanted the weapon after feeling threatened and that he paid $2200 in the dodgy deal.
He did not realise it was not a genuine firearm until he returned home, crown prosecutor Carl Young said.
Raad, Tuli and Latham all knew the buyer, the jury was told.
After the rip-off was discovered, Raad travelled to Newcastle, meeting Tuli, Latham and the buyer at another man's apartment.
The four men arranged to collect a shortened double-barrelled shotgun.
"I might be coming soon to grab them two cakes," Tuli texted the owner of the shotgun in a coded message, Mr Young said.
Unable to find Mr Nugent's accomplice - who had been thrown in custody by police on an unrelated matter - they eventually located the dealer's unit, the jury heard.
"I was just the middle man. I was just doing what I was told," the 57-year-old allegedly said moments before he was shot.
Raad stepped forward and the shotgun discharged, the jury heard.
One witness, who cannot be named, says he saw the 45-year-old loading shells into the gun before the shooting.
He denies this and also claims he did not mean for the weapon to discharge.
"It wasn't meant to happen, it was never part of the plan. They wanted their money back," his barrister Tony Evers said.
Rose Khalilizadeh and Dennis Stewart, representing Latham and Tuli respectively, said their clients denied any agreement to murder or cause Mr Nugent grievous bodily harm.Â
The eight-week trial continues.
20°C