^^^^ They don't go on sale or they have yet to go on sale? The only brand that I can truly say from what I've read up on that doesn't go on sale, sample sale included is Louis Vuitton. I remember years ago when Prada Americas Cup was so popular on majority of high end sites you couldn't order more than 3 pairs within 30 days. However, now with the model not being so sought after it's unlimited and due to the quantity they tend to go on sale. As of right now Balenciaga makes a decent quantity of Arenas that still leaves the masses wanting but unfortunately not able to get. As of right now I think Balenciaga is still not big enough for the model to become devalued, it's still pretty niche in comparison to other high end brands. I think we can all say Christian Louboutin on the other hand is devaluing it's men's sneakers.
However, the allure is so huge for them no matter if they put out new colorways each day people will still but them.