I'm not familiar with BE, but if it's anything like Plato's Closet, they target the teens and 20s demographic. Hollister > Brioni to them. Stores like that are about turnover, not quality. They don't want stuff to sit on the racks.
... and apologies for the stereotype, but the buyers (at least at every Plato's I've been to) are mostly women in their 20s/early 30s and probably not familiar with higher end menswear-focused brands. Brooks Brothers = fuddy-duddy clothes for middle aged men.
Here's another good example... just picked up an A&B myself tagged at $10 where JAB suits were all $25.
Stereotypes are common because they often have a basis in fact. Obviously, I am not suggesting that some really nasty stereotypes are accurate, fair, or should even be repeated. BUT, I think this one is pretty accurate and is not a negative stereotype. My stepdaughter is 15 and likes Plato's a lot. The times I have been in there I have observed exactly what you describe.