Nguyen Dinh Tuan, who owns an orchard in Binh Duong Province, said this season he sold the fruit at around VND30,000 per kilogram to traders.
Loan, a merchant, said prices have declined because the quality is worse than in previous years.
"I bought 300-400 kilograms of mangosteen this season, but had to lower the price to sell them because my customers complained about the poor quality," she noted, adding that the fruit also has to compete with imports from Thailand, she added.
This year, scorching temperatures and drought in major mangosteen growing areas like Hau Giang Province and Can Tho City have severely affected quality, according to local agriculture departments.
A manager at the Thu Duc Agricultural Product Market in HCMC said Thai mangosteens make up the majority of the supply at his market. Even large mangosteens can only fetch a wholesale price of VND40,000 per kilogram, 20% cheaper than Thai imports.
Due to their poor quality, local varieties are less common and often sold directly by farmers and traders instead of retailers and wholesalers, they added.