It's normally $6 as the entree for a Munchie Meal, which also comes with Halfsie fries (half curly, half regular fries), two Tacos, and a fountain drink). It's available for that price after 9 PM until 5 AM and costs $8 (may vary) outside those hours.
Unfortunately, the chicken filet was very thin, a little dry, and largely overshadowed by the cheese and jalapenos, which delivered the "nacho" premise quite well.
The two onion rings were good for a nice crunch and just a bit of sweetness.
Nutritional Info - Jack in the Box Spicy Nacho Chicken Munchie Meal (they don't list the sandwich individually)
Serving Size - 1 meal (573g) not including the drink.
Calories - 1530 (from Fat - 722)
Fat - 80g (Saturated Fat - 14g)
Sodium - 3239mg
Carbs - 155g (Sugar - 9g)
Protein - 48g