I bought from taobao, quality good and durable. We have used them for 3 years now, no damage or whatsoever as we only use them once a year in our ski trip. Really not worth the money to buy just an ordinary quality in HK, as they would be used only once in a year, and only two - three ski days.
I would think purchasing a assured good quality of sunglasses to use daily is far more essential. Ski goggles, once a year.....? Just fine enough.