Bec, our Terastations did come with Mimeo, but we haven't used it. We store directly to the Terastation (or to our video server) and we back up the Terastation and video servers to SDLT tapes (160 gigs/tape) using EMC Retrospect, which is less than $100.

I have heard very good things about Mimeo and it seemed very simple to set up, but I haven't used it.