What was the cost to develop "a working concept that converts designs to interactive code"? Zero right? Because it was just you, and you value your time at zero.
You can't "just" "value" your time more than zero. Did money go from a bank account into your pocket to develop this? No right? So it is zero. Do you have to pay rent and food either way? Yes, even if this weren't developed. So you value your time at zero. There's no psychological trick here. This is fine.
