Plotting a robbery, Christopher McEachran offered to bring a "toy" to make sure his victim handed over the keys to his prized BMW.
His friend was in need of money to buy drugs, so McEachran volunteered to help steal the car so they could sell it to get the cash.
It was a decision that will see McEachran spend at least the next five years behind bars.
Their victim was father-of-three Michael Mammone, an acquaintance of McEachran's friend.
He was lured to a car park near a Cranbourne primary school, in Melbourne's southeast, by the acquaintance - a woman he knew and trusted - in the early hours of June 26, 2020.
The woman told Mr Mammone she dropped her drugs and needed him to help find them. Mr Mammone got out of his car and was set upon by McEachran who demanded his keys.
When the woman earlier questioned McEachran about what would happen if Mr Mammone didn't hand over the keys, McEachran replied "he will because I'll scare him".
He told her he would bring a "toy", a reference to a weapon.
There was a scuffle and the woman, who later went to police to confess her part in the set-up, said she heard Mr Mammone being hit across the legs with a large knife or stick. His hands were then cable-tied together.
They fled the scene, leaving Mr Mammone's body on the ground. A knife scabbard was later found under his body.
"He's not going to get up any time soon or in a hurry," McEachran told the woman.
She asked if he was dead.
"No, he'll be alright," he replied.
When interviewed by police McEachran denied knowing Mr Mammone or having any involvement, but a police officer later heard him say "he was alive when I left".
McEachran pleaded guilty to manslaughter and armed robbery, and was on Tuesday jailed by Victorian Supreme Court Justice Elizabeth Hollingworth for nine years and nine months.
He has already spent two years in custody and will spend another five in prison before becoming eligible for parole.
Justice Hollingworth said pathologists couldn't confirm Mr Mammone's cause of death but noted one possible cause was arrhythmia while he was restrained and had ice in his system.
