"But I've noticed over the years that more people are coming in. They're realising what we're about. And they love our stock.
"We usually find that even when someone comes in just to buy a birthday present, they end up being a customer for life. We've now got girls coming in buying things for their children, because this is where their mums would shop."
Trade Aid was first established in 1973 by Vi and Richard Cottrell, whose vision was to launch a company that would trade with developing countries for fair prices, thus helping lift oppressed workers out of poverty.
Today, the organisation buys craft and food products from more than 80 collectives, which represent small farmers and artisans in Africa, Asia, Latin America and the Pacific.
Monetary support from Trade Aid assists its trading partners with improving workers' quality of life, and also goes towards large community projects, such as schools and health clinics.
In Masterton, Mrs Lee said the community has thrown itself behind Trade Aid and its ethical trading policies.
"People do like that that we're supporting artisans and small boutique farmers in the third world," she said.
"They like that we're trading for a pair price.
"The more we trade, the more living standards improve for people overseas."
The Masterton store stocks a wide variety of products, including rooibos tea from South Africa, olive oil from Palestine, coffee from Ethiopia and stone carvings from Kenya.
Mrs Lee says a particular favourite of hers are the Numdha - sheepskin rugs covered in elaborate felted designs, from the Zanana Dastkari Production Markaz collective in Kashmir, India.
"They are just beautiful. The men do all the felting and printing, and the women sew them all by hand.
"They're from way off the beaten track. And we're their only trading partner."
In 40 years, Trade Aid in New Zealand has grown into what is now a network of 29 shops nationwide, and now boasts a large online store.
Mrs Lee said the online shop has been a boost for businesses, but certainly hasn't slowed down the Queen St store's foot traffic.
"People look online, and then come in to the shop to buy what they want," she said.
"They like to touch and feel things first."
The Masterton store will be celebrating its 27th birthday on November 3 this year.