I completely agree with the above. I was surprised that the 'out of stock' function is not available. Updating everything manually takes too much time especially when we have so many listings. Even with 500 listings this is becoming a big problem.
My items remain showing that they are available, then the customer makes a purchase and then I find that the supplier has unlisted the item. This causes many problems. Firstly, if I am lucky and I will find another supplier, I still have to go through the process of finding the same item with similar shipping times, processing times and costs. What should take no more than 2 mins to place an order, sometimes can have us stressing and looking for other suppliers for many hours. Because an "out of stock" option does not exist a lot of times I have even made a loss on some sales because I could not find a similar product at the same price and the same shipping costs. For unique items this is extremely problematic because maybe I cannot find the product from another supplier.
We absolutely need an 'out of stock' option because it will be so much better if the auto updater automatically puts a product as out of stock, that way it will not be available for purchase if it is out of stock.