The number of iPhone XS Max listings on popular trading site Chotot.com as of Friday had increased by 21 percent compared to before the arrival of the first iPhone 11 models to Vietnam a month ago.

Among 20,000 phone listings on the website, which allows users to sell their used electronics products, the number of iPhone XR, XS and XS Max had surged 14 percent from three weeks before.

The website’s data also shows that more Vietnamese are hunting for older-generation iPhones at lower prices now that the iPhone 11 is in the market.

The number of search hits for iPhone X in the last three weeks has increased by 75 percent after the release of iPhone 11 models on September 10.

However, despite the expectations, the prices of iPhone XR, XS and XS Max have not dropped steeply. On the website, their prices now have only decreased by VND100,000-300,000 ($4.3-13) compared to before iPhone 11 was released.

The iPhone XR is being sold on the website for between VND9.3-15 million ($402-648), iPhone XS for 12-20 million ($519-865) and XS Max VND14.5-20.5 million ($627-886).

However, demand has also been surging for the iPhone 11 models, which are set to be officially released in Vietnam next month.

Data from electronics retailer FPT Shop show that over 6,600 customers had put down a deposit for the phone as of Saturday, a surge of 357 percent from 25 days ago.

The figure at Mobile World, another retailer, was 5,300, up 252 percent during the same period.