I really want to get After Effects. But I don't have $1000 to buy CS6. I don't want CC just because of the membership dramas and the subscription only for a year. It will be a waste because I have school and I want to use it in the holidays or free time. The best for me would be CS6 and lower because it will always be there. Is there anywhere I can purchases AE CS5 from Adobe?
No. Adobe only sells current versions. If you want a cheaper alternative/ older version, you have to find someone who is willing to sell it and run through the hoops of a license transfer.
If you're a student, I'm pretty sure Adobe has student pricing - they might even have it for a perpetual license on CS6. You should look into that.
I know you aren't that interested in the subscription model, but it sounds perfect for someone in your situation who doesn't want to spend a big chunk of money, but who wants to play around in your spare time. And, again, I'm pretty sure you can get a student discount on that too! There isn't any drama with it either. It's really a straightforward and painless process - especially when you compare it with the license transfer business.
As Mylenium says, you will have to get a used copy of CS5 or CS5.5 if you really don't want the latest version. My first concern about buying used software is making sure it's legit. Not everyone on the internet is nice, so be careful.