They are $299 on sale on the vendor website right now. I won't link because I don't want to promote them necessarily, but I think you must have seen a different vendor or something?
I also paid less than $300. OP must be referring to a different model.
Looks like they’re weirdly expensive through the EU store. Just navigate from xreal.com - I see them for $US 299
Have you looked on Amazon? I got the One (not pro) for less than £500.