Alternatives are really limited, but
1) Game Maker- It's not in .swf (flash format), so you can'tput it on AG. But it's a program to make games, if that's what you want.
2) Buy an earlier version of Flash. They will be cheaper, but might not have AS3. Not that you need AS3, but if you're going to invest money, you want to be at the top of technological chain.
3) I can't name the program off the top of my head, but there's a program very, very similiar to Flash for free. Try googling it.
4) Get the free 30-day trial. I'm not sure if this is illegal, but you can then modify your registry (if you're not an expert or don't have a tutorial you'd trust you're life to, don't even think about trying) and get the trial as many times as you want.