How Much is Too Much?

In preparation for our shipping, I am ordering large quantities of things that are difficult , if not impossible to find there, as well of articles that are overpriced. My scouting around in Beijing, in Wal Mart and in Carefour, indicated that diapers are a luxury item. They are priced at about 2$ a piece. So either it will help us get Noam potty trained earlier, chinese way or not. It could also get me to move to the cloth diaper... Which I am considering, but it is a little late to start on this as I have to try a few before investing. So alternatively I can MASS ORDER diapers for us to have when we are there. Not that I am sure where we are going to store those thought ! (there is no storage unit in our building). So currently I have an open order at diapers.com, and I am meditating on quantities... Should I order 5 ultra large boxes of size 4, size 5 and size 6? That is about 1000 units per size, and we, I estimated, go through about 6 a day. It means a supply for 155 days per size. Or a year and half supply. We are supposed to be there for 3 years. I could order more, but what sizes? At the same time, does it make sense to order so many of each size?  Should I rather order less and imagine I will move towards cloths?

I can imagine the delivery man droping 15 large boxes at our door!