More than $24,000 has been raised, including an anonymous $15,000 donation.
Campaign leader Ana Sarich said they'll bid for the land regardless of how much they raise.
According to Ngai Tupoto, the island was a former battlefield.
"It is the site of a massive battle where many many people were killed and were left to lie there when our tupuna defended our lands from attack in the past. Bones still come up there and large numbers have been interred in Remana urupa [cemetery] over the years."
Bayleys real estate agent David Baguley said he had had calls from hapu members interested in buying the land.
The Go Fund Me page said any surplus raised will be put back into the island's preservation.
"As this campaign is aimed at preserving and nurturing places of significance within the Hokianga Harbour, any surplus will be placed into a trust that will continue to do this work."
The tender closes at 2pm today.