She says customers can negotiate the prices of the second-hand items if they haven't got enough money to purchase the item at its listed price.
The shop gives Mia a space to work and means people can meet the artist behind the flax creations on sale.
She has been making flax creations since she was a child. Being of Polynesian and Māori descent, flax weaving is a tradition, Mia says.
"I'm carrying on a tradition. My nan was a weaver."
Before Soboo was opened, Mia would drive to markets to sell her creations.
"I'm grateful I have a place for my work now."
Mia's work won't be seen online, as she prefers to live her life offline.
"My motto in life is I've existed without technology and I don't need to. I also recycle as much as I can."
After the shop's operating are covered, the profit is put into a fund to give to charities, such as the Red Cross.
"I was brought up to appreciate the world," Mia says.
"My mum was an orphan after her parents were killed in World War II. She appreciated her foster parents and she spent most of her life paying forward. The Red Cross helped my mum as a child.
"They took the children that were orphans and homed and educated them. My mum was very grateful for that. She spent 28 years dedicating her time to help the Red Cross and other charities."
Mia says one of her biggest aims is to teach people that flax is a good thing.
"It can be utilised and made into something that you or someone else needs. It is also organic and is good for the environment."
■ Soboo is located on 102 High St, Hāwera.