The drives, however, are not cheap. New drives appear to start at around $1200. Used drives are all over the place -- I've seen some on eBay with an opening bid as low as $350. Also, all LTO drives appear to have either an LVD SCSI or a SAS interface, which means you'll also need a controller card. There appears to be no such thing as a SATA LTO drive.
Plus you get to re-live all the joys of selecting tape vendors, and placing bets on whose tapes are going to last for 20 years.