I think the standard Costco special is just hot dog and soda. If they have anything at all, side wise, it's probably a bag of el-cheapo potato chips.
I actually had the Costco hotdog special for lunch today - It is a 1/4 hotdog (sauerkraut on the side if you so desire and I do!!!) and a fountain drink for $1.50 American
It used to be $1.99 here. But they changed it to $1.50. The hot dog with all you can drink soda.
They also changed all the sodas. It is not very kid friendly anymore. And not very diet friendly (I think only 1 diet drink either coke or pepsi, which is the one diet drink i really don't like).
I usually end up drinking root beer since that is my fav soft drink. I actually only drink soft drinks when i eat at Costco. So that is maybe 10 times per year or less.