She had a "wonderful story to tell", Jason Arraj said.
Ms Mikhael was one of several hostages forced to record a chilling video message in front of a black Islamic flag to relay several demands required by Monis.
The mother of three had offered her story for a six-figure sum and did not "want to be insulted" with anything less, Mr Arraj said.
"It's got to be a win-win business transaction... so when I say I don't want to be - insulted, I'm saying I don't want a figure of A$10,000 - that's not going to cut it at all," Mr Arraj told The Australian.
He said Ms Mikhael would put the money towards a foundation she wanted to set up. It "is not for the purpose of making a dollar for the benefit of Marcia herself".
It emerged this week that hostages caught up in the siege will receive as little as A$1500 plus costs in compensation under the NSW victims support scheme for the 16-hour ordeal.
Marcia Mikhael, left, was forced to record a chilling video message by gunman Man Haron Monis, right. Photo / AP / Supplied
While victims of terror attacks overseas can claim up to A$75,000 in financial assistance under Australian federal law, the same legislation doesn't apply for attacks on home soil.
The maximum payments for the NSW victims support scheme were cut from A$50,000 to A$15,000 plus costs back in 2013.
Peter Hughes, who survived the Bali bombings in 2002, received federal government compensation after Prime Minister Tony Abbott backdated payments for victims of terrorist events to cover the September 11 attacks in New York.
He said the compensation had to extend to cover those caught up in terror attacks in Australia.
"It doesn't matter where the terrorism happens, it doesn't matter if it's international or it happens on our own lands, if they're Australians they should receive this help," Mr Hughes told The Daily Telegraph.
"It's not about the money, it's about showing that someone really cares and that's what I hope happens with victims of the Martin Place siege."
Flowers for Katrina Dawson and Tori Johnson, who were killed in the siege. Photo / AP
NSW Attorney General Brad Hazzard wrote to his federal counterpart George Brandis to raise the issue of compensation last month.
Mr Hazzard said it seemed strange that Australians who were the victims of terrorist attacks on home soil were not entitled to the same access to Commonwealth compensation that they would if they were travelling overseas.
The federal government would now consider extending the scheme, a spokesman for Mr Brandis said.
- Daily Mail
