Well, if it's a locker of funnel cake, I say go for the funnel cake.
However, my family really made use of the lockers last time. We went in Dec when it was a little cooler at night. We shoved our jackets and extras in there each morning and then sent 1 or 2 people to retrieve them at dusk. And - if I remember correctly - when you turn in the key, you get a refund on your locker fee. (I don't remember if it's the full amount or partial).