Haha...my old thread is back up. Anyway, What I think is a better deal is just storing your gold at home in safe and then insure it with renters insurance. For $500k worth of gold, you will probably end up paying about $200 per month give or take a few bucks. As long as gold goes up in value 50 cents every month, it pretty much pays for itself.
This sounds like a good-value idea for people serious about the size. Debaser82's idea is more economical... but who can resist haveing a door sign "Half-tonne of gold bricks is stored here"?