Just because something is expensive doesn't mean that it's overpowered. It's hard to get (unless you hack), but once you do get it; you're unstoppable.
Look you freaking annoying ass-hat: I should NOT have to spend coins on something that gives me 2-4 times more health so that I can stand a chance against people online. and just because you can kill armour noobs easily doesn't mean EVERYBODY can!!! Imagine how much for fun and balanced the game would be if literally EVERYBODY started off with the EXACT same amount of health.