Selling land to a developer/builder - establishing value

[David Brockmyre]

This is my first post since joining, so thanks for any feedback.  

I own a waterfront parcel in a great location that I want to develop into a small (10 unit) condo PUD. I would retain one of the units. My previous real estate deals were single family flips and I'm not a builder. I'm looking for input on selling to a developer. I know the entitlement and rough grade costs for this development and the market value of the future lots/units, so I'm trying to calculate a range of what a developer/builder would pay me for the entitled land before dirt gets moved. I realize costs fluctuate by market. I'm in Michigan.

Would anyone care to share how they would arrive at an asking price without just asking potential buyer's what they are willing to pay, or if a developer yourself, how do you evaluate purchases.  Any formulas you use, tips to consider, etc?

Thanks!