Most people I know spend close to $100 on cases to protect their phones and then more money invested on cases because they either get bored of their case or their case got dirty or old looking or maybe their glass screen protector broke and had to purchase another one. So my case and screen protector is AppleCare Plus!
I don't have a case or screen protector on my iPhone 6s. I didn't have one for my iPhone 6 or my iPhone 5s. I like to invest on AppleCare+ and if my phone breaks I can get a replacement (yes, I'm aware there's a deductible). Also, I change phones every year so when a new iPhone comes out, I call AppleCare, I tell them "hey I'm getting a new iPhone, I won't need a protection plan on my old one, can I get a refund for the time I didn't use it?" - Last time I believe they gave me around $60, maybe a little bit more I think close to $70, but I'm not 100% sure. It was definitely more then $50 - and then I used that money towards the purchase of AppleCare Plus for my iPhone 6S.
So yeah, no case at all here. I haven't had a broken screen ever -knock on wood- so I haven't had to shell out the money for the replacement. I just love the way the phone looks!