I think the whole thing is priced to compete against fitted bedroom furniture like Sharps where you'd pay £4-6,000 for a wardrobe, chest of drawers etc.
So here you could get a fully matching wardrobe, dressing table with a mirror, beside tables and a chest of drawers all matching here for under £2,000 and it looks like the fitted stuff.
The mirror is pretty expensive as an individual piece but the point is it matches the other stuff and it would elevate the whole thing so is I could see why some people could make the case to themselves.
Clever marketing. YOu see it in kitchens all the time too.