Property broker Warren Hutt, of CBRE, said the resort would go on the market in a few weeks but wouldn't comment further.
Carter, one of five siblings and step-siblings who inherited the camp from their parents, the campground founders, Dawn and Vaughan Harsant, said he hoped the new owner would keep the site as a "good tourism resort", including space for tents.
The family had secured a 45-year structure plan to make it "more viable as an accommodation resort".
"But we've got to be realistic. Whoever buys it, they've got their own choices."
Asked how much he thought the resort would sell for, he replied: "Moonbeams".
A Coromandel real estate agent and property adviser anticipated a huge raft of development potential for the existing campground facilities and amenities and associated flat land used for caravan and tent sites.
That could include being retained or used for budget and mid-range accommodation. "Some of the peripheral land - particularly that with direct waterfront access - could be subdivided and developed into high-end coastal lifestyle blocks.
"With limited beachfront land available in and around Hahei, these blocks would certainly be sought after."
The campground could also be shut and converted into a high-end, privately owed holiday enclave with private beach access.
"As with most New Zealand coastal campgrounds, the value of the asset is far more in the landholding than the business operation."
Thames-Coromandel District Council district plan manager Leigh Robcke said if the new buyer developed using an already approved structure plan for the site they would have "additional development entitlements" above those available to someone subdividing under coastal village zone rules.
That included a 10m height limit in some areas, allowing for "things like visitor accommodation apartments". Height limits for coastal village zone properties were 8m but getting consent for that and other "basic building envelope rules" would not be insurmountable.
"If people want a quick buck then they'll potentially look at doing a subdivision," Robcke said.
Thames-Coromandel mayor Glenn Leach hoped the Hahei buyer would keep it "tourism-related".
Hahei General Store co-owner Pauline Verran said campers helped swell the settlement from a permanent population of 350 to 6,000 in summer.
Their business would take a hit if the campground closed.
Hahei Holiday Resort isn't the only slice of paradise under threat from development. Whangamata Motor Camp, also more than 50 years old, went on the market last month.
