Apple doesn’t want want you to buy their headset (opinion)
So, there are only a few apps for the headset at the moment and they are all first party. Apple needs developers to make apps for the headset before they start selling it in mass.
If they do not have apps for it, then people will see a “dead” ecosystem and possibly view it as a failed product.
They priced it at a point where consumers won’t really get it, but devs will. At least larger devs will. Selling it, shows the devs that it’s ready for the market and encourages them to get in early so they can possibly catch the wave of new users.
Once there are a decent amount and variety of apps for the headset, they will sell a slightly trimmed down version for significantly less.
I think the whole point of having the headset priced in this range was to make sure that the experience really is very good. I'm sure thet they could've made this juuuust a little worse and therefore a bit cheaper (e.g., leave out the eye display to the outside, use one or two cameras less etc).
But then, everyone using it would probably be like "meh, this is nothing special, maybe AR isn't there yet" and abandon the idea. I think the first impression really matters here.
In the end, it's a feedback loop: If noone develops apps for this, there are no apps and nobody wants to use it. If nobody uses it, nobody wants to develop for it.