We've been through this... the economy is in the tank. In order to make the product line profitable this year based on reduced sales units, the price had to increase. The other choice was likely to moth-ball the product line.
Adding to this is the fact that Apple doesn't operate on the same thin margins that Dell does. Dell is a mail-order company. Apple offers a premium experience that goes well beyond the product to include their retail centers and their support and training.
Also, doing industrial product design to the degree Apple does is not cheap. For example, there's the case internals redesign (have you ever seen a cleaner case inside?)... this translates into improved cooling which means less noise. Which reminds me, there's the cooling system redesign which is much more sophisticated than a single exhaust fan running at jet like speeds. And then there's the motherboard... which is obviously not just an Intel reference design like Dell is probably using. It's a custom Apple designed board with integrated I/O, SATA backplane connectors, integrated power for a PCIe graphics card, etc. This stuff doesn't come for free!!!
I cry at the lack of appreciation for what goes into making a stellar product here.