Here in the states, Harbor Freight has had them for sale every couple of months at a little less than the cost plus shipping in that ad. Around $6.49 last time I remember. Since he is in China he might live around the corner from the factory and buying them at a good rate.
A member form China, on another forum who makes fancy light fixtures with Swarovski type crystals. Has Said the economic down turn has hit some of the industries and locations harder than others there. And they are trying to figure out ways to move the merchandise that is already made and in warehouses waiting to fill the orders before it all went.
Like when I was making and wholesaling Magic tricks, I told somebody I could sell 20 at a show and make a buck each, Or I could make .50¢ each and sell 60 or 70. Some times the numbers only work when the profit is slim!