I'm not a fan of LV rtw, but I pretty much like every other category though. My opinion, most clothing items from designer brands are not worth the price tag. Fabrics tend to be the same across brands and sometimes fast fashion brands will offer higher quality variants of the same fabric type. Also, keep in mind that the "made in ___" label for any brand only refers to where the product was finished and exported from. The fabric and buttons could have all been made in a third world factory, for all we know.
On average, clothes have a lifespan of 2 years of regular use before they should be replaced, emphasis on regular. If you want to buy a fancy dress for a special occasion, go for it. If it's jeans you plan to wear every week, might as well go for something "cheap" but maximizes your money. Clothing fads also change, faster than bags in my opinion. That sweater you like right now might look outdated in two years. Would you be ok with spending all that money only to have a piece of clothing that looks dated? What happens if you gain or lose weight? Most rtw pieces feel very consumer and look like basic sewing patterns to me...
That being said, I understand that what you're mainly paying for is the design house's aesthetic and name. If you truly love the brand and everything about the item, then why not. If you like the brand but feel the quality is cheap, it's probably not worth your coin at all. You have to love the item completely.
I'm not a fan of expensive rtw but I do love couture/haute couture. Designer rtw just feels like another variant of rtw fast fashion. While many fast fashion brands do take inspiration from more expensive brands, clothing brands tend to take function and norms into consideration. You can only push the limit so far before you alienate a large group of consumers. Couture, for me, is really where designers will let their creativity shine. There are some crazy pieces out there, but I love it. Someone has a blouse with
gucci or lv screen printed, cool, but a dress that moves like a kinetic sculpture (Iris Van Herpen) or a full hand-embroidered train (Guo Pei), that's something you truly don't see every day.
But I do love and appreciate rtw on the run way and on other tpfers. 
