since the G5 and the case have long been discontinued, you'll most likely have to search around for a used Ikelite case. I'd post up WTBs on all the popular u/w photo sites and see if anyone bites - digideep, wetpixel, underwaterphotography.com, scubaboard are all good places to try. but I wouldn't pay $400-$500 to house a G5. You can snag a new G7 and Canon housing for close to that.