A new example just added to the resources section shows an interesting real world example of a retailer offering identical products at different prices... just feet away from each other at the same store.
The retailer is a large electronics/entertainment store and the product is digital movies (DVDs and Blu-Ray discs). They often offer the same version of a movie on a well organized, easy-to-navigate, alphabetized rack, and again in a chaotic, unorganized discount bin. One is presumably targeted at the customer who is looking for a specific movie, the other targeting the impulse buyer who might make a purchase when they have finished their shopping or are waiting to check out.
Which presentation targets which customer? And which one is likely to pay more? It is a very interesting way of letting customers segregate themselves according to how they value the product, thereby increasing sales without cannibalizing sales at the higher price.