"It was a calculated and deliberate deceit," Foster told the judge.
"Rather than marketing exclusive rights to those products, he was engaged in a clear course of criminal offending which had him identifying victims and then making a series of misrepresentations to them for the sole purpose of extracting large payments from them."
Duffell didn't stop when confronted by the victims, she said. Instead, he continued to court other victims, and in the last case, befriending him, with their wives also becoming friends. After being told something was awry, the victim asked for his money back.
"This defendant reassured him and told him that he would refund the money but immediately moved to transfer $120,000 from his New Zealand bank account to an Australian bank account.
"The final victim who paid $137,000 ... continue, to this day, to pay interest to the bank on that amount ... they are a family with young children, who lost their family home in circumstances they could no longer afford to make payments."
His offending only stopped when the victims identified each other and went to police.
Duffell benefited financially by $319,400, however a further loss of $71,900 was caused to the first victim as she had the original, or master, licence to the product.
Foster argued Duffell had expressed little remorse and as the case had stretched three years he should get minimal discount for a guilty plea, Foster argued.
However, his counsel Tom Sutcliffe disputed his client was not sorry for what happened.
"He's a man who has been a hard worker all his life ... is the father of seven children and a grandfather and continues to be a provider for them and has been in full-time employment."
Duffell's offending started with his "desire to be self employed and to be successful financially", but he never set out to deceive.
"It was a programme that was in continual stage of development and it morphed into different products as time went on."
He accepted that she'd asked for her money back, but as he didn't have the money he undertook to try and sell what he had sold her and continued to market the licence.
"He was desperately trying to make a success out of something which he firmly believed could be successful ... he started out with the very best of intentions and through ill discipline, failing to take proper legal advice ... he was led to error and that simply became a pattern of conduct."
Not only had the victim's lost money, but Duffell's had too and now that he - the sole breadwinner - would be going to jail, their family home may also be lost to the bank, he said.
The $120,000 was transferred to buy an apartment due to the amount of time he was spending in Australia for work.
However, Judge Connell had little sympathy, describing Duffell's treatment of his victims throughout the offending as "callous and cold".
He said the victims were ambitious and wanted a solid income stream for their families, however each failed "because there was no such thing as an exclusive right".
"I can't believe that you are so callous or cold that you couldn't have at least had some understanding, I accept that you now do, of the damage you have done to other families both in terms of their financial position but also in terms of their psychological [state]."
Duffell should have known what he was doing was wrong after selling on the rights to the second victim.
"You should have taken the right path instead of going down the path of this horrendous fraud."
Aggravating Duffell's position was the fact he wasn't in a position to pay any reparation to the victims.
The software packages involved were Quick Office Pro, Tradesoftware and All Trades Pro.
