Okay, the simple example is jeans. I not a big spendy-mc-spenderson, but I prefer to buy expensive jeans. By expensive I mean like $50.
Oh boy, okay, this gets more complicated because I also am a creature of habit, which might be part of this.
I buy my jeans at the GAP. It makes things simple for me. I wear a six (except for my first 6 months of living in nyc when I had no money, ran 5 days a week to have activity, and shrunk to a 4, in the "curvy" style). In my closet I have 6 pairs of jeans, 1 Gap 4, 1 Gap 8, 3 Gap 6's, and one pair of other expensive jeans I bought while out shopping with friends at PeachFrog. They are all over a year old (except for the PeachFrog pair) and they are all aging perfectly.
They haven't shrunk. The fabric has gotten softer, but not stretched out. They haven't worn out at the knees (that takes about 5 years, I got rid of pairs from high school last year, because the holes finally spread all the way across the knee).
I have a friend who buys jeans at H&M. They have shrunk shrunk shrunk. And the fabric starts to feel pill-ey. I like H&M for some things, like jersey dresses, and when I need a great stylish cheap top to wear to a wrap party. But don't buy jeans there. they are cheap cheap cheap.