Plextor PX-256M5S M5 Series 256GB Solid State Drive for $169.99 shipped.  Here is a screenshot for your reference.  Alternatively, it is available at Newegg for $169.99 shipped.  It features up to 520 MB/s read speed, 390 MB/s write speed, 512MB cache, and uses SATA III interface.  It usually goes for about $199.