Dan Areily in "Predictably Irrational" calls this the 'anchor effect.' That an opinion of something is transmitted when linked to something similar.

Starbucks broke an anchor effect by making their stores about ambiance. As a result, customers were willing to spend double the usual price on the same coffee--or of slightly higher quality--because the anchor was broken from Dunkin' Donuts' coffee. It was a different experience and therefore, a different price scale was acceptable to customers.