Q: How to put listings out of stock instead of a certain price?
A: Go to your Marketplace Settings (Settings --> Marketplaces --> eBay) and change this option from 999 to 0. Save Settings. See the image below.
You'll need to go into your eBay account and up at the top left is your name. Click that, then click Account Settings --> Site Preferences --> Selling Preferences and make sure that the Use Out of Stock Control option is checked. If this option is not checked, ebay will not allow your listings to be set to a quantity of 0.
Also note that your listings have to be GTC (Good Till Cancelled) listings from the start. They cannot be fixed duration (i.e. 30 day listings) or previously have been and then changed to GTC as eBay only allows listings to be treated how they were originally listed. Fixed duration listings cannot be set to a quantity of 0.
After you have made any necessary changes, go to your Sku Grid account and do Batch Options --> Force All Items to update to push all items to be updated according to your new settings. If OOS, then they shall be placed out of stock instead of set to 999.