Maybe it has to do with perceived value - kind of like buying a bottle of wine to give to the host when you're invited to somebody's house for dinner. You don't buy the $6.99 bottle of wine becaues that's too cheap. You get the $16.99 bottle of wine to hit the middle price-point and think that it must be better just because it cost more. It turns out that the cost of a bottle of wine has little to do with how good it is. With the higher markup, a buyer thinks he is getting more.
Come to think of it, speakers and wine are similar in, at least, a couple of ways. 1) Higher price doesn't always mean better sound/taste. 2) You should get what tastes/sounds best for you within your budget.
-Dave
