I bought one for $12, which is the same price as their 14" large limited-time pizzas.
The cheese was very mild but provided decent coverage and not a bit of stretchiness (as is typical of chain pizza). The sauce was thick and tended toward the sweet side of things.
The crust was fairly thick all around with a definite chewiness and didn't crisp up much. The end crust doesn't hold up all that great if you have leftovers as it was already pretty dry on day two.
Nutritional Info - Papa John's XL Monster Toppings Pizza
Serving Size - 1 slice (156g) / 10 slices per pizza
Calories - 390 (from Fat - 170)
Fat - 18g (Saturated Fat - 7g)
Sodium - 1010mg
Carbs - 41g (Sugar - 5g)
Protein - 15g