mwave offers the Sans Digital TowerRAID 4-Bay Serial SAS / SATA RAID 5 Storage Enclosure, model no. TR4X+BHA, for $309.99 with free shipping. That's $23 under our mention from a month ago and the lowest total price we could find by $30. It supports four 3.5" SAS or SATA hard disk drives and features a PCI-Express 4x controller, over 300MB/s read write performance, and more.