Sans Digital TR4M+BNC 4-Bay eSATA Port Multiplier Tower Storage Enclosure for $59.99 shipped after promo code EMCXSVR73 and this $30 rebate.  Here is a screenshot before the $30 rebate for your reference.  It features eSATA interface and provides the ability to access four hot-swappable SATA hard drives via single eSATA connection.  Most places have this hard drive enclosure [...]