Thomas Elvin, 51, from Meenacargagh, Ballybofey told the investors he could make millions through his company Pear Shaped Resources.
But the scheme collapsed, leaving investors out of pocket.
He was found guilty at an earlier trial of illegally operating an investment scheme on various dates between 2003 and 2005.
During his trial Elvin, whose Pear Shaped Resources was based in the British Virgin Islands, claimed he was a penniless bible-believer who wanted to raise millions for benevolent causes.
He operated from a computer on his farm through Internet contact with a US aide, Larry Marsella who had a plan to raise 25 per cent profit a day on high-risk investments on international currency exchanges through a system known as ForEx.
Elvin admitted in court that he hoped to turn 50,000 dollars into 98 million dollars between 30 and 45 days but Marsella, whom he trusted, duped him.
Judge O’Hagan was told that €38,000 from “frozen” money had been repaid to one female victim who lost €102,000 to Elvin. None of the rest of the cash was ever recovered.
The case was adjourned until today for sentence at Letterkenny Circuit Court during which he was facing 28 charges.
Senior Counsel for Elvin, Desmond Murphy, said sending his client to prison would be of no benefit to those who had been left out of pocket.
“Whatever slight chance there is of people getting their money back – he can’t do that if he is in prison. None of the investors will get their money back and it will cost the state a considerable amount of money,” he said.
Barrister Murphy read a short statement from Elvin in which he asked to allow people to let him get their money back saying “Please allow me to be a giver.”
However Judge O’Hagan said Elvin’s plan was sophisticated and elaborate.
“This was an elaborate, sophisticated and deliberate fraud of these good people. He took advantage of them because they had the same fate as him.
“They are good, God-fearing people and they trusted Mr Elvin up to the hilt and that he would look after them.
“This was an absolute pipe dream engineered by Mr Elvin and he comes in here and he says he planned no wrong. Every penny went to his benefit.”
Judge O’Hagan added that it was a serious case of deliberate deception.
“It’s a lot of money and for what? Nothing. Absolutely noting except pain, grief and loss of money by these good people and others.
“I am asked to keep him out of prison. What message would I send out to deceivers if I was not to send him to prison?” asked Judge O’Hagan.
During today’s sentence, Judge O’Hagan was made aware of two further charges against Elvyn for operating as an illegal investor in 2007.
During that fraud, Elvyn pleaded guilty to taking more than €30,000 from a woman on two occasions.
Judge O’Hagan sentenced Elvin five years on each of twelve charges of operating as an illegal investor.
He also sentenced him to three years for each of a further fourteen charges of obtaining money by deception.
He sentenced him to a further 10 years for the later charges entered for offences which occurred in 2007 – also for operating as an illegal investor.
All sentences are to run concurrently which means Elvin will serve a total of five years in prison.