The freeware is worth
almost as much as you pay for it -- okay for making banner ads (sort of) but not much else. There are a couple of low-priced (under $100) alternatives that have something of the power of Adobe Flash, notably
SoThink SWF Quicker, that will allow you to create real interactive elements and are free to download for evaluation (movies are watermarked, and no, I'm not endorsing the product).
I'd suggest forgetting you ever heard of Flash, though, since you can do most things another way and you're going to lose audience (Apple mobile devices, including the iPhone and iPad, do not support Flash). I'm sure I'm not the only user who has FlashBlock enabled -- you'd have to be offering something pretty compelling in order to get me to allow Flash to run on your site. Keep Flash for games. If you're using it for anything else, you're doing it wrong.