Holaplex supports the creation and sale of prints of NFTs-- digital copies of the master edition. There are two ways to create and sell prints. One, open editions (which can be read about here), and two, limited editions.
Open edition sales allow you to create as many prints of a master NFT as you want and sell them for a fixed price. During the sale's time frame, anyone can mint a copy of the NFT for the price you determine. You retain ownership of the master edition NFT.
To sell open edition prints on Holaplex, select Open Edition as your auction type. From there, the steps will look very similar to a standard auction setup.