A frequent means used to secure costly stock to put out a damaged demonstration stock, or a sampler or a replica on the counter with the box but keep the actual stock for sale in a secured location.
Typical stock would be items like mobile phones, jewellery, expensive pen, etc. Only if the customer is keen, do you bring out the actual item when it can be demonstrated with a trusted staff member in supervision. As such the odds of stock getting shoplifted is considerably lowered
This is how you mark that an item is to be treated like this.
Go to stock maintenance and then catalogue, you will see there are a list of these very specialised item categories.
Tick secure.
There are plenty of other options there and I do suggest that you run them too as they maybe useful as well.