Mwave offers the factory-refurbished Sans Digital MobileSTOR 4-Bay Diskless RAID Enclosure in Silver, model no. MS4UT+, for $69.99 with free shipping. That's $98 under the lowest total price we could find for a new one. It features four hot-swappable 3.5" drive bays with up to 12TB storage capacity, eSATA, USB 2.0, USB 3.0, RAID switch, and 3" ball-bearing cooling fan. A Sans Digital 90-day warranty applies.