So I'm not the only one who saw it and started planning out how to make it, and in what colours and patterns then? Excellent!
I can understand some high costs for doll clothes, especially when they are more detailed and even more especially when they are detailed and for smaller sizes, as they can be fiddly little things to do; and I have some doll clothes, (mostly from Dollheart) that are far better made than some of mine

Balancing that out is that less stuff (fabric, trimmings etc) is needed. But whichever way I cut it, $400 seems very expensive for that outfit, however gorgeous it looks! And it is stunning. I have one character who wants that now, and one on the way who would probably look good in it, too. In both cases scaled down to MSD size.
Remember, the reverse of stressed is desserts.
Growing older is mandatory. Growing up is optional.