I picked one up (in the wee hours of course!) for $1.79.
It's not too different from Jack's regular Tacos and/or Monster Tacos since the only real difference is eggs instead of lettuce.
Overall, I enjoyed Jack in the Box's Breakfast Monster Taco, which adds an interesting quirk to the late night classic. I'm not entirely convinced it feels like breakfast but it was good.
Nutritional Info - Jack in the Box Breafast Monster Taco (135g)
Calories - 324 (from Fat - 191)
Fat - 21g (Saturated Fat - 7g)
Sodium - 668mg
Carbs - 19g (Sugar - 3g)
Protein - 14g