Expensive does not equal durable. Compare to cars: a Formula 1 car costs millions, and essentially needs to be fully rebuilt after a couple of races, whereas a Toyota truck will cost significantly less money, and will
survive anything bar a nuclear assault. The F1 car maximizes certain properties (speed) at the expense of others (durability, loading space, price).
It seems to me this is the same for luxury fabrics. In the drive to create higher super numbers and thread counts, durability is very often lost. When you are sufficiently wealthy, that's not a problem, you order 50 shirts in one go. When you're an upper middle class StyleForum baller who also has a mortgage, student debt and child care to take care of, things are a bit different.
Personally, I try to go for the Skoda deal: what will look good, be reasonably priced (but not necessarily cheap) and get the job done without me having to fuss too much. In fabrics, that means that I gravitate towards anything that is not marketed as a super for suitings/jacketings, and 100/2 thread count or lower in shirts.