You can mix and match high and low and it's all good. But it's not an apples to apples comparison. Almost any mass-produced garment will have better "quality" than a small, artisanal maker, of course, but to me fashion is about how a garment makes me feel as much as it is about the intrinsic "worth" of that garment. In other words, I expect my clothing to do double duty -- make me look good and make me feel good at the same time.
I would be happier wearing that Ten C than I would wearing that Timberland coat. Every day. So, for me, the question often comes down to: How much is my happiness worth? 600 euros over the life of a coat? Perhaps, perhaps not.