In my opinion you should buy CE only if you want spend a lot time in abyss at lv 30-40 without loosing adventage in flight time. If you want grind for high lv or crafting you will spend most time in "safe" arenas which you don't need this time flight. My ranger is at 36lv and i didn't bought CE and wings for lv 30. If i need flight somewhere where 1 min is not enaugh i just use wind serum. 1 milion kinah is also big ammount but at lv 40+ your grinding will bring you much more kinah to buy missed skills or wings. I am concentreted on griding and campaing quest so i don't need wings, think about it.