It seems like the China tourists to Malaysia have developed a love for Malaysian durian, so much so that they are buying the fruit at the Malaysians farms they visit, and the Malaysian farmers themselves exporting more of their harvest to China. With this competition from a relatively new market, what this means is that prices for durians has steadily increased.
Naturally, the Malaysian farmer will sell to the highest bidder, thus Singapore's share of the Malaysian durian market may be shrinking, with Malaysian suppliers selling more of the fruit to China. Now, durian lovers here might have to pay higher prices for the durian. Another price increase, and this time, China plays a part in it.