Why are 100 Corona gold pieces cheaper?

[ShortJohnSilver]

At tulving.com the 100 Corona, Austro-Hungarian pieces which are almost 1 ounce apiece are selling for $8.95 over the spot price of the gold they contain.

Do dealers (assuming you wanted to cash some of them for instance) know about them? Why are they cheaper than e.g. Krugs?

[undgrd]

I've noticed that with many dealers selling them. Maybe they don't move so they're trying to get them to move? Not much demand for them?

[gunDriller]

gold is gold.

it seems like sometimes, these temporary discounts for coins that are "out of favor" eventually disappear.

for example, the 2 Rand coin, same weight as the Sovereign, .2354 oz., used to sell about $10 or $15 cheaper than the Sov. (e.g. March 2010). that gap closed up.

can't help but wonder if the same thing will happen with the Corona - or with the Mexican coins that seem to have a lower spread.