How can I get a previous version of EA?

You can't get the previous version. But why do you need it?

All new versions are back comparable to the previous ones. So, you can achieve the same result and even more with new version. The only thing you may need — is corrected set file. Please, ask the community for help if you have any troubles with converting.

If you are looking for the previous version just to compare the results, please contact me with your set and tester configuration (ini file), I'll check it for you.

And yes, you shouldn't upgrade to every new version if you don't need new features. Just work with the version you have.