You get the best valve, thermometer, and sight-glass arrangement out there IMO. You have to factor those costs and all the fittings into the equation to compare apples to apples. A legally acquired keg costs around $75-100, then add all the parts onto the list and you are spending a bit less than the Blichmann's but in my opinion do not have as nice a set up.
The false bottom looks to be the best design available and the stepped bottom ensures a good seat. Basically, you are paying for a professionally designed and assembled tool that is specific for the job it is doing.
Keggles work great, that is what I currently use. But I illegally procured my kegs before I knew it was illegal and piece mealed my crapped together system for a couple years. In hind sight, I would have saved my money until I could affoard a nice kettle (Like the Blichmann) and bought what I really wanted the first time around.
Others will likely be here in a minute to tell me you can brew the best beer in the world for $0.50 and that they don't need to spend a bunch of money to make great beer. That is true, but I like having nice tools. It makes the hobby WAY more enjoyable IMO.