Motukaraka Island, being sold by Bayleys, has a CV of $85,000 according to the real estate company's website.
The website says the island is best known as a seafood bounty bursting with flounder, oysters, cockles, pipi and snapper.
Ms Sarich, who lives on the Gold Coast, said the island was also a wahi tapu (sacred place) which is why local hapu Ngai Tupoto were keen to see it turned into a public reserve.
"I learned that it was the site of an ancient pa many years ago.
"It was also the site of a battle and when warriors died, they left their bodies on the island."
Ms Sarich said she was coming home to attend a hui this weekend where the sale of the island and details about the GoFundMe page would be discussed.
Ms Sarich said she was inspired to create the page after $2 million was raised in a Givealittle campaign last year to buy 7ha of private beach at Awaroa Inlet, which was then made part of Abel Tasman National Park.
She said whanau had researched other options, like going through iwi and trusts, but that did not look promising.
"I thought let's put it out there and see if we can crowd-source some funds to buy it.
"The fear is we might lose it to foreign hands or they might pull the sale altogether and lose the opportunity to buy it back."
Ms Sarich said whanau would be attending the auction, scheduled for Wednesday, April 26, to let potential buyers know about the history of the island.
She said the money raised would go into a trust.
If someone else was successful in buying Motukaraka Island that money would be held and potentially used for other historic sites in the Hokianga Harbour.
All of those details would be discussed at this weekend's hui.
Vist www.gofundme.com/buybackmotukarakaisland for more information.