This monitor was well over $22,000 when it came out last fall. This has almost 8x the resolution of an 18" TFT (1280*1024) - and is priced about the same as 8 TFT's. IBM is selling enough of them to cut their costs on these monitors.
In regards to the question as to why 15" and 18" TFTs have not fallen in price is because demand has gone up. Consider the iMAC uses TFT's, and third tier clone makers like Dell and Gateway include 15" TFTs on lower-end systems. As a result, demand on 15" panels has gone up - manufacturers can't make enough. Costs have gone up on the actual panel by about $100 since Christmas as people bid for them.
For the folks that want big screen TVs or Plasma Monitors - the resolution is about 800*600 - you'd need 20 of them to match the resolution of the IBM T221.
When you laugh at a price point like this, ask yourself who has added the most innovation in the computer industry, and that you are paying for some of that research in these products. Then consider how much Dell has added to the process - the more support Dell gets, the more gets driven out of the product - no more innovation, no more new products, no more new anything. I look at the level of support I got from Dell 15 years ago, and what I get today, and it is a lot less today - Dell is squeezing every nickle out that they can. Granted you get lower prices, but remember that "you get what you pay for".