For the Americans (myself included) 500g is about 17.5 ounces or 1 pound & 1.5 ounces. I'm sure we'll only be able to do a one pound bag. I am shopping tonight so I will check but I think it is $2.00 USD. Damn we're expensive.
Interesting what different places use to check food prices, here it's normally a gallon of milk ($3.50 - $4.00), a loaf of bread ($2) or a dozen large eggs ($2.00-$2.50) (prices are for generic / no frills brands, higher brands will cost more).
Edit: I am also in a metropolitan area (city) so prices here will be higher than the norm, plus other areas are more expensive than here (I'm in Fort Lauderdale, FL, areas like Los Angeles and New York City will be more expensive).