I definitely think that if items like this are going to be available primarily through chance based mechanics, that there should at least be an option to buy the full set (for a slight markup), and not just half of it.
It's enough of a shame that you only have a chance to obtain half of the set without buying premium currency, but being forced to gamble your money on maybe getting some of the other half of the set is pretty frustrating.
I was excited when I saw this set, I love the art and the aesthetic. But I can't justify spending money on *maybe* getting some of the items, so I might as well not even bother.