Former Prime Minister Tony Abbot even took to Twitter to remark that politics should be kept out of sport.
Speaking to Channel 9, Macklemore spoke about music power to bring a message to a wider audience and help affect change.
While the funding arrangement has not been formally worked out, the United States rapper said the idea to donate to the "yes" camp came to him in the vehicle on the way to the media opportunity on Saturday.
Macklemore has been pulled into the national marriage equality debate after it became known he would be performing the pro-marriage equality track at the NRL grand final.
Both Turnbull and opposition Labor leader Bill Shorten support marriage equality, as do the leaders of every one of Australia's eight states and territories.
"Yo the NRL hooked me up, I got some Tim Tams, I got some Arnotts, I got some ANZACs, I got some koalas, some of these", the rapper said in the video.
"Anytime that you announce a performer, it's going to be in front of 80,000 people, there is going to be some people that are like "oh why don't we have this person", that just comes with the territory", he said.
She argued homegrown heroes such as John Farnham should be given top billing at the NRL Grand Final.
Musician Macklemore's 2012 single "Same Love" has surged up to number one on the Australian iTunes charts, after politicians hit out at the U.S. artist for politicising sport amidst Australia's same-sex marriage debate.
Mr Abbott's latest intervention was echoed by North Queensland MP Bob Katter, who accused the NRL of using the decider to "promote their sexual proclivities".
Senior coalition figure George Brandis criticised Mr Abbott's selective backing of free speech and described calls to have the rapper's performance banned as "bizarre".
Yesterday someone started a petition in Australia to ban me from playing Same Love at the #NRLGF.
Amid the row, the song has risen to the top of the Australian iTunes chart.
Meanwhile, Macklemore is aware of the furore, telling Los Angeles hip-hop radio program The Cruz Show he's been getting tweets from "angry old white dudes in Australia".