Hey thanks (I'm the author)! BTW the "Pro" version has the electrochromic dimming, so I recommend paying a little extra for that unless you're really sure you're not going to need it.
EDIT: To clarify, I meant the "Xreal Air 2 Pro", not the "Xreal One Pro". The latter are much more expensive.
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've been thinking about using xreal glasses for coding but all the reviews I've seen seems to think that the fidelity isn't good enough for reading text for lengthy stretches of time. This article is the first counter argument here.