The older Apple monitors are not worth the price. You can get Dell monitors, sometimes with the exact same panel that the Apple ones use, for like half the price. However the Apple monitors have the aluminum colored bezel so they more closely match the Macbooks in style and looks, and that justifies the price sometimes if style is very important and you can afford the premium.
The new Apple monitor, the 24 inch LED one, is actually priced quite low, believe it or not. Remember, this is a 24 inch LED monitor. The only other 24 inch LED one I've found is a Samsung that goes for around $2000. For the technology, it's almost a steal. This is NOT the same technology used in the Dells, HPs, and Samsung monitors you can find at Best Buy and other stores. Those monitors use the older CCFL technology.