At the time of creation, NFTs can have a sale price, although there are also collections that are minted for free.
Beyond the price set by the creator, once the items are released into the market, supply and demand will determine the exchange price at any given moment.
There are people who engage in buying and selling NFTs and make money in the process, but there are also individuals who incur losses, so it is always advisable to act with caution and gather as much information as possible.
The price of an NFT is influenced by various market conditions: the utilities it provides, whether creators and the community are interested and engaged in the collection, the state of the market (bear market; bull market), and countless other factors, as the market is the result of multiple human interactions.