Same hot dog and a refillable drink at Costco still just $1.50. Buy a huge bag of chips and it's still cheaper and you've got enough for several people.
Better yet, a churro for a buck and/or a yogurt or sundae or whatever else they've got that looks good. Better and cheaper. Costco has cheap pizza by the slice too.
Not that I'm advocating eating at Costco, it's not really a great dining experience. Nor is JDawgs or the fast food places for that matter.
The JDawgs deal is probably no worse than what the burger places charge. Burger and fries is probably better than hot dog and chips though.