Dragon pouches. Buy them once to store your outfits. I bought my premium because of queue and queue only. I don't see necessity of wardrobe because I don't use it and I do just fine. Later in game, I might buy some more dragon pouches to store more outfits, and I'm perfectly fine with that. If you are running low on inventory at this point, that just means you're not managing it correctly. Only open boxes when you need them, grind things you don't need, and sell mats that you don't need at the moment.