Stock going in and out works on a weekly cycle. But, the only way to ensure that you are in the queue for items is by ordering them ahead if they are out of stock. I make multiple stock orders a each week, and I'm always adding peoples' custom orders onto those orders. Then it'sa matter of playing the waiting game - sometimes a week is all it takes to bring an order to completion, other times it takes a second week and for truly troublesome items it can take a bit longer. Some people place two orders: one order for stuff they see is in stock [and Step 3 of the checkout will show you this again to be certain] and a second order for things they want the Forge to order in for them. Why miss out on something when you can just order it in and have it reserved for yourself.