Oh yeah another thing, if hes a cool dealer (100 an ounce is great by the way) he might knock a bit off the price if you buy a QP, which is 4 ounces. So Id guess that for 5 ounces, 100 an ounce, he'll probably sell you it for like $430 or something.
Unless hes already selling it really cheap.
And if you do go ahead and buy 5 ounces, MAKE SURE HE WEIGHS IT OUT IN FRONT OF YOU!!! It can be pretty hard to tell the difference between 5 ounces and 4.5