Please see this thread about EdenFantasys' product selection
. There is some good information here about what Eden is doing with its stock. They are in the process of eliminating some items, adding others, and reducing duplicate stock.
Also, please try to remember that Eden is a retail store. Even though they're not selling the same kind of products we do, I see a lot of the same trends here as I do in the store where I work. High demand items will always sell out quickly when they come in because people have been waiting for them. There will be a delay to get that product restocked again because it takes time to get another order from the manufacturer, who may have to make more to fill their own orders.
On the flipside, if it took a really long time to sell out of another item, it may not be advantageous to restock that item when they could use that money/space in the warehouse to increase stock for that high demand item everyone wants.