Couldn't I buy a 12 pack of hot dogs, 8 pack of buns, and a 2L bottle of soda for like $3 combined or something? A hot dog isn't much work to cook.
When you find that deal, let us know.
If you insist. You all got me curious*, and I went and took a walk to the nearest grocery stores and checked prices. I don't think my estimate was that far off. Also, now thanks to this thread, I guess we'll be grilling hot dogs this weekend.
Apparently hot dogs and buns are more expensive than I thought, but I still don't think the Costco hot dog deal is "screaming hot deal" or anything.
I bought seven hot dogs, and eight buns for $3.04:

I could have got cheaper I could have got more expensive, but this was me randomly walking to the nearest store, not shopping for the cheapest deal.
We already have soda at home, but adding a two liter bottle of no name cola would have been $0.70:

For reference, a pack of hot dogs at the grocery store seemed to vary from $1.99 to $5.99

The buns cost $1.37 which seems kind of a waste of money for white bread and empty carbs:

At the Dollar Tree next to it, hot dogs and buns were even cheaper starting at $1.50 for a pack of hot dogs, and 85 cents for the buns:

I'm sure they are fine, but I didn't buy the hot dogs at the Dollar Tree, because I thought Dollar Store hot dogs sounded sketchy .. didn't stop me from getting the empty carbs there :)
Obviously, if you like the Costco hot dogs as a prepared meal, go ahead and buy them. Nobody is stopping you**, but unlike the rotisserie chicken, I don't think this is cheaper to get prepared than it is the raw ingredients (If I'm bored again, maybe I'll do as similar work up for the rotisserie chicken, but as seen up-thread, I think other people have already examined this).
*Also, son wouldn't nap, so strapping him to me while I walked around pedantically checking prices seems to have bored him to sleep. So win - win.
** Well the waste on the single serve soda kind of bothers me, but I used to work at a cup factory, so I have a sore spot for disposable plastic lids, etc