I decided to check one of my local grocery stores because I honestly wasn't sure where they stood relative to each other.
Most Little Debbie varieties, for a standard package containing 6 or 12 items depending on the size of the items, are listed at $3.19.
Apples are commonly sold in 3 pound bags, which the internet suggests would contain 6-12 apples depending on the variety of apple and individual sizing. The 3 pound bag seems like a reasonable comparison to the standard Little Debbie packages, as it's 6-12 "snacks" in either case.
The cheapest option is Red Delicious at $3.99. You can spend up to $6.99 for 3 pounds of a more premium variety.
Little Debbies cost $0.26 to $0.53 per snack. Cheap apples are $0.33 to $0.66 per.
The advantage is also present with larger quantities. A large package of Little Debbie snacks costs $5.49, and a 5lb bag of Red Delicious apples costs $5.99. You're getting 2x the Little Debbie snacks in the larger package, but you're only getting 66% more apples in a 5lb bag.
At the larger quantity, LD's per snack price range is $0.23 to $0.45. Red Delicious apples are $0.30 to $0.60.
Calorie wise you'd need to 2-3 apples to equal most Little Debbie snacks, but in terms of satiation the opposite is true.
Maybe I should have compared individuals then. One apple can be had for less than dollar and one snack cake is over a dollar
Either way people should be eating apples, bananas, pears (as well as cheese, nuts...), instead of snack cakes.