Oftentimes, the best thing about brand names isn't about the look but about the fit. Yeah, a plain white American Apparel tee is 15 bucks more than a Hanes one. But the Hanes one is baggy and uncomfortable, whereas the American Apparel one fits well, thus causing it to look better.
If it's the type of item that I would like to be durable then I would favor the branded item because I can be assured of the quality. Even if the fabric is the same the stitching might not be given as much attention during quality checks when it comes to cheaper brands, but in general I think clothes are a lot more forgiving. For me, shoes are one one of the things where it pays to get a good brand because they last longer that way anyway.
I would not pay more for an identical item, just for a name. The only way I pay more for a brand name, is if it is showing a difference, a better quality of fabric or design or sewing skill.
I have to agree that name brand clothes are quality clothes and they are made better from better fabric, so in the end they do last longer, thus saving you money. I have a few classic pieces of clothing that are brand names that I bought over 15 years ago. They are holding up great. On the other hand I have some pieces from Joe Fresh that are falling apart and only last a season or two. I think when I buy clothes from stores like Joe Fresh, I know they won't last and will have to be replaced in a few years.
I think it definitely depends on the brand. A lot of brands are just better quality over all. For example I find the jeans I buy at Old Navy only last a few washes compared to if I invest in a higher quality better name brand. On the other hand, I find items like tshirts to be pretty generic anywhere I go. I can easily get a few a Target or a spend money on a designer brand but they both serve the same purposes. The only thing I usually do invest in is shoes. I find brand name shoes are not only more comfortable but also last a lot longer than shoes I buy that are no name brand.
I used to shun branded clothes in favor of imitation. But when my nieces have grown up, I had learned how to value branded clothes not only for the style but for the durability. Besides, wearing imitation is just like fooling people. There is an abundance of fake apparel here which makes branded clothes appear cheap. The most popular branded clothes now are those new arrival with no imitation yet.
If I had money and didn't have to think about the price tag all the time, I'd go with the branded clothes a lot more often. The items may look identical to the naked eye, but up market and branded clothes tend to be more durable, better quality and better cut and designed. If you can't immediately see it, you'll feel it in the way they fit. If it's just for lounge wear, I don't mind going as cheap as I can. But for clothes I wear out, I really prefer nicely tailored clothes.
I think that the answer to this is very subjective. If you have the money, and you are surrounded by people who constantly reinforce the idea that brand names are the way to go, then of course those people are going to believe that those brands are worth the money. Personally I think that you can get clothes that are just as good quality as those that are brand names. Most of the time people are paying for the name, and not the quality of the product.
