Is 400$ for an iphone 6 from tmobile a good deal?

I'm buying from a good friend of mine because my phone is all cracked and i need a new one. He bought it 2 months after it came out.

Seems pretty steep to me. If he used a turn in site it would be 200 bucks. Why charge you double. Not sure if he is being a good friend asking for 400.

Its cracked so you have no idea how much damage was done