One of the beauties of the Arduino is that the design is very simple- all that's really needed is a couple of capacitors, a resonator or crystal, and the ATMEGA328 itself. Here in the USA, there's an outfit in Texas that sells "AnArduino", which is a bare-bones implementation, for about ten bucks off ebay with all the needed parts and a little PCB even.. basically a Boarduino without the voltage regulator. The point is, you can buy 328's with the bootloader already flashed and build an "arduino" into it permanently for around ten bucks, if you want a project as a dedicated item.
That being said... yeah... where's the insane sales? I need a $5 oscilloscope... I'm so broke I can't even pay attention... hehehe