Don't buy, download it. Bit Torrent works really well. I used AE for like 2 years with premiere as an effects tool. So I would edit a vid. without adding effects in premiere, and then put it into AE to do all the effect work. It is pretty sick, but I had to get a book to learn how to use it. I would recomend getting:
It is really good, and you learn a ton really quickly.