Where can I find a DIY kit to make a robotic hand?

[SuperRobot]

Well, I'm studying computer engineering but I also really love Robotics and Electronics, even if I'm just a really new beginner.
I really learn things by doing projects, so I'm really interesting in making my own robotic hand (that can move electrically, buttons, sensors, etc.) before deciding to really go into this section also. (That's how I went to programming, by doing a CMS in php, it was very hard even if some people can do it in 3-4 hours, I was with 0 knowledge).

I have found a few things, but wow, this category is really expensive. My budget is around $120.00 for this project.

I have seen some amazing robotic hands, that I wish I could do in the future, such as:
http://www.youtube.com/watch?v=qLqq5Eul ... _embedded#!
I really LIKE THAT SO MUCH, I would even invest my whole salary on it if it was enough.(Talking about the first link)
http://www.youtube.com/watch?v=y2tXNksz ... re=related
http://www.youtube.com/watch?v=e2WEVo9YzVE

I know isn't easy, but please something easy to understand (as easy as possible).

Thanks A LOT.