How much to replace a lost iphone 5s?

So I lost my phone a few days ago and my parents are not willing to buy me another one considering how expensive the first one was. I was just wondering how much it is to replace it? Because isn't it cheaper to replace a phone than to buy a completely new one? Also, I believe there was a special deal going on right now regarding the replacement for iphones or for 5's but I'm not sure what the deal was exactly.

1) WHY are you posting this "question" in the category for cars & transportation?
2) If you lost your phone, you have to buy a new one. "Replacing" is only for a defective phone.
3) If you have to ask, you can't afford it.

Unless you're getting it off craigslist expect to spend a lot of money