I have spent waaaayy too much. I have candyshell, pixel skin, one of the frogz cases that broke, an incipio ngp, mophie juice pack plus and a couple other $5-10 cases from amazon and eBay. I have a **** load of different colored bumpers and transparent cases. I've probably got about 35-40 cases and bumpers. I've also bought six different colored back replacements and a bunch of decals. I'm addicted to modifying my phone =/ I've spent more on cases and decals and backs than the cost of the phone lol
And the sad part? I don't use any of them anymore. I just put on a colored back replacement and use it with a zagg screen protector now. Sometimes I'll put a bumper on it if I'm going to concerts or parties because the iPhone is pretty slippery and I don't want to accidentally drop it while drinking.