In your experience how much does an extra bedroom cost?

[D'Wayne Hopkins]

The main question is in the title. I'm potentially doing my first deal. I wanted to buy this duplex but since my credit is trash and I don't have any savings I passed it on to my cousin to flip. A couple conversations later and I'm actually participating in the deal. That said, there's an unfinished basement in the property on both sides. In your experience, how much would it cost to add a bedroom in that part of the house?

I'm in the Kansas City market if that makes a difference.