The body of Josh Tunnicliffe (27) was found near a park bench in the gardens on November 4, 2012.
Police referred his death to the coroner, after gas canisters were found near his body.
Following his death, his parents spoke of their son's decade-long battle with huffing.
''He died with so little, and on his own,'' his Auckland-based mother Jenny Lee, told the Otago Daily Times at the time.
Blair Marsh, of Dunedin, said his friend's death ''still hits me every day''.
Mr Tunnicliffe lived with him and his young family for six months, and his death ''has had a big impact on me''.
The pair began smoking synthetic cannabis every day after work, but Mr Marsh was not aware his ''best mate'' was also battling solvent abuse.
It wasn't until he until started to find butane cans around the property, that ''I had to put my foot down and ask him to leave because I had four kids to protect''.
''I tried my hardest to get him help. But he would just tell you what you wanted to hear, but he didn't want to accept help.''
Whenever he contacted Mr Tunnicliffe, he always seemed to be ''on a park bench somewhere in Dunedin''.
Mr Marsh was able to stop his legal high addiction following the death of his friend.
Mr Marsh had asked permission from the council for a bench to go in the gardens and Mr Tunnicliffe's parents supported the idea.
He was now raising the $2500 needed for the park bench via the crowd-funding website Pledge Me.
