That's not the point, they have nothing on their website saying what you can and cannot buy with certain NX cash, truth be told you can (quite literally) buy nothing besides clothes if you paid with Paypal, Click & Buy or any other credit/debit card method.
I'm thinking of suing them for false advertisement.
But on a more serious note it was intended as a present for my sister, as I already said, buy a few incubators with my last five pounds, sell the scrolls from them and give her the money, but such a nice gesture was lost on Nexon and I finally realised why everyone hates them.