Because the upper is the part that stands out most. So it may be reasonable that is costs more.
Plus, the devs are definitely hungry for income, and they realize that people will financially support them.
Personally, it makes me not want to purchase MC. If this is how the pricing is going to go, I have a bad feeling they might increase all the prices (HC and MC) for all items, and I dislike that thought greatly. Just because a piece 'stands' out more, doesn't mean it should be nearly the cost of the special cosmetic chassis with special textures on them. However, I'm sure they realize how expensive a lot of the stuff on the market already is... The real question is what they do with it.
EDIT: I really want that chassis, but I honestly dislike the price. It's not a good bargain, and I'd hate to not support my favorite game, but this just kills it for me.
Edited by Hijinks_The_Turtle, 17 April 2015 - 10:12 AM.