Mwave offers the iStarUSA Serial ATA 6Gb/s Hot-Swap RAID Cage, model no. BPU-230SATA-BPL, for $48.99 with free shipping. That's a buck under our mention from two weeks ago and, outside of the mention below, a current low by $12. It's also the best price we've seen. This hot-swap capable chassis enclosure fits two 5.25" drive bays, holds up to three 3.5" hard drives, and supports RAID.
A close price: Newegg offers it for $49.99 with free shipping.