Craigslist.
You can either find a used laptop loaded with the CS suite or find someone to install it on your existing computer. I did that in the past. But remember, you get what you pay for, and there are all sorts of interesting people on craigslist who may not have any idea of what they are doing and load your computer up with viruses.
For the monthly subscription to the Adobe cloud, I would never go back to pirate software again. It will always work, and always be updated.
For sep software, that may be a tough find.
Accurip is lower priced rip software (I'm assuming you don't have a rip program and you will need that if you intend to print halftones).
Quickseps is on the lower side of sep software. There are also a lot of great people on this forum that can sep stuff for you at very fair prices