Buying something based solely on the label is definitely not only a waste of money, but also a mindless thing to do. Now it's fine to take the brand into consideration before making a purchase. I got a portable air conditioner years ago, and of the various choices, picked an Amana brand as it has a good reputation....but user reviews, price comparison, and other factors were part of the decision.
Overpaying for a certain brand name bluejeans is stoopid. Paying $500,000 for a pair of Stuart Wietzman Diamond Stilettos is exponentially more stupid. So far as I can see, the only benefit is in stroking your own ego, or impressing your egotist faux friends with your conspicuous consumption....like lighting a cigar with a $500 bill as seen in Hollyweird movies.