It is just stupid how fast questions get answered here. I've never seen a place so helpful and full of people who know what they are talking about. HUGE thanks.
Are 6 x 9 enlargers significantly more costly by chance?
It is hard to say since any enlarger would be expensive to ship to China. The most common in the US is the Beselar 23c which isn't any more expensive than any other medium format enlarger. Any 4x5 enlarger will work also. I see that Lucky makes one in China. It will be much less expensive if you can find one in Shanghai.