Sun-YY:
Arduino original board is so expensive. I want to purchase one from ebay because the price is much lower. However as the guy above said it must be fake. I bet it must came from China which is the biggest manufacturing country in the world. Then i prefer to choose one with brand even if it came from China for the good price and support.
Arduino boards are good deals. Consider also the huge amount of effort that goes into developing and supporting the IDE, this forum, etc. etc. There are also good quality clones available from numerous reputable vendors (Adafruit, Evil Mad Science, PJRC, Modern Device to name just a few).
For the person just getting into microcontrollers, buying the original and supporting the Arduino organization is pretty much a no-brainer. The last thing I'd want when learning is to question whether a problem is mine or is the fault of some hardware of questionable origin.
Once some experience is gained, the Arduino Pro and Pro Mini ($15 and $10 from Sparkfun) are good values, or design your own custom boards. Let us know what it costs you to do that, and don't forget to factor in your time!