Starting with the SHOCKING REVELATION THAT....
Step 1: For a microcontroller, the Arduino is NOT CHEAP!
1. the Arduino is NOT a cheap microcontroller!
When Arduino-lovers like me say "Wow, the Arduino is such a cheap microcontroller!" this is not strictly true -- it is very cheap for what it is, but type "microcontroller" into Mouser's search box and you will find microcontrollers that cost 30 cents, not 30 dollars.
(go to next page)
Step 2: The Arduino is NOT a microcontroller!
2. The Arduino is NOT a microcontroller!
Of course, the Arduino is not a microcontroller, but rather a development environment for microcontrollers -- including a programmer board, a software program for the computer, and a programming language, in addition to the microcontroller chip itself. A programming/debugging solution the Arduino is extremely easy and friendly to use, and the level of support you get with it is well worth the money. But really, the term "microcontroller" refers specifically to the ATMEGA chip that is on the Arduino debug board. All the other stuff on the board (the fancy power supply, the LEDs, the reset button, the programming circuitry, the USB-to-Serial converter) is totally optional.
Could that possibly mean that....