Apples/Oranges. The Hulk at best would be an exoskeleton covered with a rubber skin with limited articulation and very little fabric. Iron Monger would be casted in solid pieces to look right with not even an Exoskeleton underneath (they didn't with Iron Man) and would be three times heavier. There is a lot more engineering that would need to occur to make Iron Monger to scale and looking right while The Hulk is just the same engineering as was already done with their other figures and especially Hellboy just expanded to a larger degree.