Three different products get sold under that phrase, and it's worth naming them the same way every time.
A 3D walkthrough is captured with a camera that records depth as well as image, from a series of tripod positions through the property. The output is a navigable space the viewer clicks through, usually with an overhead dollhouse view. Matterport is the best known system, Zillow's 3D Home is a phone based version of the same idea. That's your $340.
A video walkthrough is a linear edited clip. Someone walks the property with a gimbal, it gets cut to music, the viewer watches from start to finish with no control over where they go. That's your $145.
A 360 photo tour sits between them, a set of panoramic stills linked room to room, cheaper to produce and with no real spatial model behind it.
Strictly, only the first two of those are what the industry means by immersive. Loosely, MLS systems have a field called virtual tour link that will accept any URL, including a slideshow of stills, and that field is where the sloppy usage comes from.
On showings, a 3D tour does filter out people who were never going to like the layout, which matters most on a vacant unit an agent has to drive to. It also invites a question you should be ready for. Those systems generate room measurements, and they're approximate. Don't republish a captured square footage as the unit's official size, since what you can advertise as square footage and how you must qualify it varies by state and by MLS rule. Take the measurement from your own records instead.
