I would not buy it, to be honest -- only because I can tell that you are new to it --- which doesn't mean that it's bad, it just has some flaws, but you've done an excellent job in your intro!
If I created it for a client and charged them, if that's what you mean, I would just do the math for 20 bucks an hour.
If I were to buy it from you, like a template? then no more than 50 dollars.
The colors are plain, the font is plain (get off the arial usage), the animation is rather basic, and probably a little much (I think I saw four different font animations?). The colors/layout/ and font are what give it's newness away. I would work on checking out other flash stuff and see what they're doing. Also check out animation that you see in commercials, tv, movies... etc. Try and figure out how they did certain things, and what's common and what's not.
For a first shot, it's excellent, but I would not pay much for it. Hope that doesn't offend you, it's not meant to