Screw tape... you pay $2,000 USD for the drive, $50+ per tape for a couple of hundred gigs.
Go with bare drive external: Install a trayless SATA bay for 3.5" hard drives... this will run you $12. Buy some bare SATA drives.. these run $50 for 1TB and are available up to 3TB. I buy bare drive hard cases for about $3 each. My Intel ICH10R on-board RAID controller supports hot-swap -- so in effect it's a big 3.5" floppy.. that's right.
If your tape drive breaks, you're out another two grand. This is far less expensive, faster, higher density, and random access. In addition, you can boot from it.
Want RAID0? Install two trayless SATA bays for a total of $24 and back up in pairs.