If your listing duration is set to Good ‘Til Cancelled (a default option when you create a product via GeekSeller), the listing will show up to buyers until you’ve sold all your items. When that happens, the listing will end and you will need to pay a fee to list it again. However, if you regularly get more stock of that item, then you should use the out-of-stock option. Your listing will then be hidden from search results, but as soon as you increase the quantity again, the listing will reappear in searches and no fees will be applied.
If you enable out-of-stock-option option shown below, this will allow GeekSeller to set qty 0 on your products on eBay.com. See a screenshot below where you can find it. For more information about this option visit https://pages.ebay.com/help/sell/multiple.html#outofstock.