It costs a princely £43.24 from CCL
http://www.cclonline.com/product/105451/Z9-PLUS/Cases/Zalman-Z9-Plus-Midi-Tower-PC-Case/CAS0788/
Or you can get the version with front USB3 for £54.98 from Overclockers.
http://www.overclockers.co.uk/showproduct.php?prodid=CA-056-ZA&groupid=2362&catid=736
[EDIT] The USB3 version from CCL
http://www.cclonline.com/product/14...Z9U3-Black-Mid-Tower-Case-ATX/M-ATX-/CAS1463/
You are my Faerie godmother!!! Going for the bottom one!!!