RAID 5 Server????

I'd really like a file server w/ RAID 5. I obviously don't have the funds or need for a hardware raid array. I'm looking for 500 GB to 1 TB of space just to store music, videos, and other files that I don't want to lose. I'm just looking for the most cost effective way to do this. I'm fine with running linux, but I'm just curious what type of machine would I need to start with, and what kind of cost do you think I'd be looking at to get that sort of space?

Thanks a lot.