More than 800 people inspected everything from ballroom curtains to coffee cups after the castle's overcrowded attic was cleared out for the first time in nearly 50 years.
Those wanting the more sought-after items, including mantles, stools and a porcelain toilet, arrived early at 10am, while a queue stretched back along the castle's entry road shortly after 11am.
One of those in the queue was Barbara Blake, of Dunedin, who was pleased to find bundles of cutlery for $1 each.
They would be used in her caravan and she thought, jokingly, it would be nice to have something "fancy" for it.
"I love the castle, I think it is a really neat part of Dunedin," she said.
Another lover of the historic home was Destiny Williamson, who picked up serving platters, cake stands, a stool and a table at the sale. "I love the castle. I love the garage sale," she said.
Marketing manager Deborah Price said it was a "fantastic" day, with sale proceeds paying for entertainment including horse and carriage rides, a magician, band, and bouncy castle.
About 75% of the items in the sale were sold. An antique walnut bed was among the unsold items. A discussion would be held to decide the future of the leftovers.
"It [the sale] served a really good purpose. We needed to get rid of it and it's great when people are happy because they are getting a really good bargain," she said.
