For fractional gold, I'd say go for 1/10 ounce.
$15-25 premium isn't all that bad, in my opinion.
As far as gold being used as currency in the future, it will happen again. Precious metals have been used since Biblical times, and it's only within the past century (past half century for silver) that the precious metals have left world circulation and/or lost convertibility via paper money.
It is absurd to think that fiat currencies will last in the long run. We're already seeing massive debt bubbles form and printing of money at unprecedented scales, worldwide...due mainly to the fact that no currency is restricted in any sense by the amount of money that can possibly circulate and reasonably be converted on demand.
Fiat currencies may have had their run, and we may see massive sovereign defaults soon coupled with nations reverting to precious metals, or we may see them replaced with new fiat currencies to try the system again; but whatever should be clear to anyone, is that if it's next week, next year, or a century or two in the future, fiat currency will die and be replaced by what it itself replaced.
<--Thinks that whatever the case may be, it's a good thing to have precious metals to protect wealth, and with that said, you really shouldn't pay a 100-150% premium on your precious metals (Aurum are approximately 250% of spot price, and with the volume discount, the cost is approximately double spot price). That makes no sense...1/10, 1/4, 1/2, 1 ounce of gold can be melted down into smaller units if need be, it'd be a better use of money to invest in graphite ingot molds and whatnot needed to melt coins or rounds down yourself (should you ever find yourself in such an economic apocalypse to warrant it)
All my
Two Cents. Take it or leave it.