yohji yamamoto, or just go normcore and get some straight cut dad jeans and some addidas
For real though, what you get when you buy designer clothing depends wholly on the brand. If you're buying something like Loro Piana or Brunello Cucinelli you're getting basically the best made clothes money can buy, but perhaps not necessarily the most fashion forward. If you're buying Saint Laurent, it's much more about how directional the clothes are and how they fit versus the quality, which while being very good, is not the end all be all. Sometimes designer clothing are all mark up, and just hype. I've never seen a designer t shirt that was worth the price on the tag.
One of the biggest things with designer clothing though is quality control. I've heard stories about how four different pairs of the same levi's jean in the same size will all fit differently, how stitching is fucked up on H&M shirts. That basically doesn't happen with designer clothing, and if there is some mistake, or a piece falls apart too quickly, the designer will almost always replace it for free.
Putting it nicely that shirt is... not good. And if you want to wear that shirt, that's all well and fine, but it seems weird to come in to this thread, ask for advice, and then when everyone tells you not to wear South Pole ignore that advice completely. We're just trying to help!