I can compare domains to property! Whether it’s a car or a piece of real estate, it is intellectual property. And it has a value.
No matter the property, you have to have a place to put it. A car goes in the garage. Real estate belongs at an address. Domains/websites live at an IP address on the web and a host is a garage.
The costs to purchase a car, building or a domain, all come at a price (new or pre-owned).
Most new domains are relatively inexpensive, unless they are premium names. Owned names may be a bit higher (owners will have you at least pay for their original fees).
You never really 'own' a domain. You lease it for a year at a time, max for ten years. And NO, you don’t have to keep domains forever, if you don’t want to.
So if you have your dream name, start your search. If it is available, Buy it, don’t wait. It might not be available for very long. If someone else owns it, contact them for sale.