Think of the "Astronomical" rents as a marketing expense and it makes a lot more sense.
The crazy thing is that some of these apple stores actually break even.
the location of the apple store is why people will pay several hundred dollars more for a Mac or a iPad when a similar PC or Tablet gets you 90% of the features and functionality.
it's the association with luxury.
again, all marketing.
Apple is not a luxury brand.
You can make the case for "Premium" but not "Luxury".
Bottom line, if your wares are sold at Walmart you're not "Luxury".