高端大气上档次 are three words. 高端 means high level. Such as a five-star hotel. 大气 means generous or openhanded. 上档次 means good grade. Actually, these three words means the similar meaning that it is a better thing than normal one.

这是新创的网络用词，不能按照字面去翻译和理解，应该按照大概意思翻译为英语 Very Noble.一般多用来讽刺人的.如果是口语那就是Very Very Noble

高端 means high-end 大气 means luxury 上档次 means meeting a high standard.

It's same!

The following translation of the phrase is spreading widely on the Internet. Haha. Not sure if it is correct. Luxury, Large, Level up. In short, we call it LLL or 3L.